In the final blog in this series, we’ll focus on step five of the OneFS firewall provisioning process and turn our attention to some of the management and monitoring considerations and troubleshooting tools associated with the firewall.

One can manage and monitor the firewall in OneFS 9.5 using the CLI, platform API, or WebUI. Because data security threats come from inside an environment as well as out, such as from a rogue IT employee, a good practice is to constrain the use of all-powerful ‘root’, ‘administrator’, and ‘sudo’ accounts as much as possible. Instead of granting cluster admins full rights, a preferred approach is to use OneFS’ comprehensive authentication, authorization, and accounting framework.

OneFS role-based access control (RBAC) can be used to explicitly limit who has access to configure and monitor the firewall. A cluster security administrator selects the desired access zone, creates a zone-aware role within it, assigns privileges, and then assigns members. For example, from the WebUI under Access > Membership and roles > Roles:

When these members login to the cluster from a configuration interface (WebUI, Platform API, or CLI) they inherit their assigned privileges.

Accessing the firewall from the WebUI and CLI in OneFS 9.5 requires the new ISI_PRIV_FIREWALL administration privilege.

# isi auth privileges -v | grep -i -A 2 firewall
         ID: ISI_PRIV_FIREWALL
Description: Configure network firewall
       Name: Firewall
   Category: Configuration
 Permission: w

This privilege can be assigned one of four permission levels for a role, including:

By default, the built-in ‘SystemAdmin’ roles is granted write privileges to administer the firewall, while the built-in ‘AuditAdmin’ role has read permission to view the firewall configuration and logs.

With OneFS RBAC, an enhanced security approach for a site could be to create two additional roles on a cluster, each with an increasing realm of trust. For example:

1.  An IT ops/helpdesk role with ‘read’ access to the snapshot attributes would permit monitoring and troubleshooting the firewall, but no changes:

For example:

# isi auth roles create IT_Ops
# isi auth roles modify IT_Ops --add-priv-read ISI_PRIV_FIREWALL
# isi auth roles view IT_Ops | grep -A2 -i firewall
             ID: ISI_PRIV_FIREWALL
      Permission: r

2.  A Firewall Admin role would provide full firewall configuration and management rights:

For example:

# isi auth roles create FirewallAdmin
# isi auth roles modify FirewallAdmin –add-priv-write ISI_PRIV_FIREWALL
# isi auth roles view FirewallAdmin | grep -A2 -i firewall
ID: ISI_PRIV_FIREWALL
Permission: w

Note that when configuring OneFS RBAC, remember to remove the ‘ISI_PRIV_AUTH’ and ‘ISI_PRIV_ROLE’ privilege from all but the most trusted administrators.

Additionally, enterprise security management tools such as CyberArk can also be incorporated to manage authentication and access control holistically across an environment. These can be configured to change passwords on trusted accounts frequently (every hour or so), require multi-Level approvals prior to retrieving passwords, and track and audit password requests and trends.

OneFS firewall limits

When working with the OneFS firewall, there are some upper bounds to the configurable attributes to keep in mind. These include:

Firewall performance

Be aware that, while the OneFS firewall can greatly enhance the network security of a cluster, by nature of its packet inspection and filtering activity, it does come with a slight performance penalty (generally less than 5%).

Firewall and hardening mode

If OneFS STIG hardening (that is, from ‘isi hardening apply’) is applied to a cluster with the OneFS firewall disabled, the firewall will be automatically activated. On the other hand, if the firewall is already enabled, then there will be no change and it will remain active.

Firewall and user-configurable ports

Some OneFS services allow the TCP/UDP ports on which the daemon listens to be changed. These include:

The default ports for these services are already configured in the associated global policy rules. For example, for the S3 protocol:

# isi network firewall rules list | grep s3
default_pools_policy.rule_s3                  55     Firewall rule on s3 service                                                              allow
# isi network firewall rules view default_pools_policy.rule_s3
          ID: default_pools_policy.rule_s3
        Name: rule_s3
       Index: 55
 Description: Firewall rule on s3 service
    Protocol: TCP
   Dst Ports: 9020, 9021
Src Networks: -
   Src Ports: -
      Action: allow

Note that the global policies, or any custom policies, do not auto-update if these ports are reconfigured. This means that the firewall policies must be manually updated when changing ports. For example, if the NDMP port is changed from 10000 to 10001:

# isi ndmp settings global view
                       Service: False
                           Port: 10000
                            DMA: generic
          Bre Max Num Contexts: 64
MSB Context Retention Duration: 300
MSR Context Retention Duration: 600
        Stub File Open Timeout: 15
             Enable Redirector: False
              Enable Throttler: False
       Throttler CPU Threshold: 50
# isi ndmp settings global modify --port 10001
# isi ndmp settings global view | grep -i port
                           Port: 10001

The firewall’s NDMP rule port configuration must also be reset to 10001:

# isi network firewall rule list | grep ndmp
default_pools_policy.rule_ndmp                44     Firewall rule on ndmp service                                                            allow
# isi network firewall rule modify default_pools_policy.rule_ndmp --dst-ports 10001 --live
# isi network firewall rule view default_pools_policy.rule_ndmp | grep -i dst
   Dst Ports: 10001

Note that the –live flag is specified to enact this port change immediately.

Firewall and source-based routing

Under the hood, OneFS source-based routing (SBR) and the OneFS firewall both leverage ‘ipfw’. As such, SBR and the firewall share the single ipfw table in the kernel. However, the two features use separate ipfw table partitions.

This allows SBR and the firewall to be activated independently of each other. For example, even if the firewall is disabled, SBR can still be enabled and any configured SBR rules displayed as expected (that is, using ipfw set 0 show).

Firewall and IPv6

Note that the firewall’s global default policies have a rule allowing ICMP6 by default. For IPv6 enabled networks, ICMP6 is critical for the functioning of NDP (Neighbor Discovery Protocol). As such, when creating custom firewall policies and rules for IPv6-enabled network subnets/pools, be sure to add a rule allowing ICMP6 to support NDP. As discussed in a previous blog, an alternative (and potentially easier) approach is to clone a global policy to a new one and just customize its ruleset instead.

Firewall and FTP

The OneFS FTP service can work in two modes: Active and Passive. Passive mode is the default, where FTP data connections are created on top of random ephemeral ports. However, because the OneFS firewall requires fixed ports to operate, it only supports the FTP service in Active mode. Attempts to enable the firewall with FTP running in Passive mode will generate the following warning:

# isi ftp settings view | grep -i active
          Active Mode: No
# isi network firewall settings modify --enabled yes
FTP service is running in Passive mode. Enabling network firewall will lead to FTP clients having their connections blocked. To avoid this, please enable FTP active mode and ensure clients are configured in active mode before retrying. Are you sure you want to proceed and enable network firewall? (yes/[no]):

To activate the OneFS firewall in conjunction with the FTP service, first ensure that the FTP service is running in Active mode before enabling the firewall. For example:

# isi ftp settings view | grep -i enable
  FTP Service Enabled: Yes
# isi ftp settings view | grep -i active
          Active Mode: No
# isi ftp setting modify –active-mode true
# isi ftp settings view | grep -i active
          Active Mode: Yes
# isi network firewall settings modify --enabled yes

Note: Verify FTP active mode support and/or firewall settings on the client side, too.

Firewall monitoring and troubleshooting

When it comes to monitoring the OneFS firewall, the following logfiles and utilities provide a variety of information and are a good source to start investigating an issue:

Note that the preceding files and command output are automatically included in logsets generated by the ‘isi_gather_info’ data collection tool.

You can run the isi_gconfig command with the ‘-q’ flag to identify any values that are not at their default settings. For example, the stock (default) isi_firewall_d gconfig context will not report any configuration entries:

# isi_gconfig -q -t firewall
[root] {version:1}

The firewall can also be run in the foreground for additional active rule reporting and debug output. For example, first shut down the isi_firewall_d service:

# isi services -a isi_firewall_d disable
The service 'isi_firewall_d' has been disabled.

Next, start up the firewall with the ‘-f’ flag.

# isi_firewall_d -f
Acquiring kevents for flxconfig
Acquiring kevents for nodeinfo
Acquiring kevents for firewall config
Initialize the firewall library
Initialize the ipfw set
ipfw: Rule added by ipfw is for temporary use and will be auto flushed soon. Use isi firewall instead.
cmd:/sbin/ipfw set enable 0 normal termination, exit code:0
isi_firewall_d is now running
Loaded master FlexNet config (rev:312)
Update the local firewall with changed files: flx_config, Node info, Firewall config
Start to update the firewall rule...
flx_config version changed!                              latest_flx_config_revision: new:312, orig:0
node_info version changed!                               latest_node_info_revision: new:1, orig:0
firewall gconfig version changed!                                latest_fw_gconfig_revision: new:17, orig:0
Start to update the firewall rule for firewall configuration (gconfig)
Start to handle the firewall configure (gconfig)
Handle the firewall policy default_pools_policy
ipfw: Rule added by ipfw is for temporary use and will be auto flushed soon. Use isi firewall instead.
32043 allow tcp from any to any 10000 in
cmd:/sbin/ipfw add 32043 set 8 allow TCP from any  to any 10000 in  normal termination, exit code:0
ipfw: Rule added by ipfw is for temporary use and will be auto flushed soon. Use isi firewall instead.
32044 allow tcp from any to any 389,636 in
cmd:/sbin/ipfw add 32044 set 8 allow TCP from any  to any 389,636 in  normal termination, exit code:0
Snip...

If the OneFS firewall is enabled and some network traffic is blocked, either this or the ipfw show CLI command will often provide the first clues.

Please note that the ipfw command should NEVER be used to modify the OneFS firewall table!

For example, say a rule is added to the default pools policy denying traffic on port 9876 from all source networks (0.0.0.0/0):

# isi network firewall rules create default_pools_policy.rule_9876 --index=100 --dst-ports 9876 --src-networks 0.0.0.0/0 --action deny –live
# isi network firewall rules view default_pools_policy.rule_9876
          ID: default_pools_policy.rule_9876
        Name: rule_9876
       Index: 100
 Description:
    Protocol: ALL
   Dst Ports: 9876
Src Networks: 0.0.0.0/0
   Src Ports: -
      Action: deny

Running ipfw show and grepping for the port will show this new rule:

# ipfw show | grep 9876
32099            0               0 deny ip from any to any 9876 in

The ipfw show command output also reports the statistics of how many IP packets have matched each rule This can be incredibly useful when investigating firewall issues. For example, a telnet session is initiated to the cluster on port 9876 from a client:

# telnet 10.224.127.8 9876
Trying 10.224.127.8...
telnet: connect to address 10.224.127.8: Operation timed out
telnet: Unable to connect to remote host

The connection attempt will time out because the port 9876 ‘deny’ rule will silently drop the packets. At the same time, the ipfw show command will increment its counter to report on the denied packets. For example:

# ipfw show | grep 9876
32099            9             540 deny ip from any to any 9876 in

If this behavior is not anticipated or desired, you can find the rule name by searching the rules list for the port number, in this case port 9876:

# isi network firewall rules list | grep 9876
default_pools_policy.rule_9876                100                                                                 deny

The offending rule can then be reverted to ‘allow’ traffic on port 9876:

# isi network firewall rules modify default_pools_policy.rule_9876 --action allow --live

Or easily deleted, if preferred:

# isi network firewall rules delete default_pools_policy.rule_9876 --live
Are you sure you want to delete firewall rule default_pools_policy.rule_9876? (yes/[no]): yes

Author: Nick Trimbee

PowerScale OneFS 9.6 now brings a new offering in AWS cloud — APEX File Storage for AWS. APEX File Storage for AWS is a software-defined cloud file storage service that provides high-performance, flexible, secure, and scalable file storage for AWS environments. It is a fully customer managed service that is designed to meet the needs of enterprise-scale file workloads running on AWS.

Benefits of running OneFS in Cloud

APEX File Storage for AWS brings the OneFS distributed file system software into the public cloud, allowing users to have the same management experience in the cloud as with their on-premises PowerScale appliance.

With APEX File Storage for AWS, you can easily deploy and manage file storage on AWS, without the need for hardware or software management. The service provides a scalable and elastic storage infrastructure that can grow or shrink, according to your actual business needs.

Some of the key features and benefits of APEX File Storage for AWS include:

• Scale-out: APEX File Storage for AWS is powered by the Dell PowerScale OneFS distributed file system. You can start with a small OneFS cluster and then expand it incrementally as your data storage requirements grow. Cluster capacity can be scaled on-demand up to 1PiB. 
• Data management: APEX File Storage for AWS provides powerful data management capabilities, such as snapshot, data replication, and backup and restore. Because OneFS features are the same in the cloud as in on-premises, organizations can simplify operations and reduce management complexity with a consistent user experience.
• Simplified journey to hybrid cloud: More and more organizations operate in a hybrid cloud environment, where they need to move data between on-premises and cloud-based environments. APEX File Storage for AWS can help you bridge this gap by facilitating seamless data mobility between on-premises and the cloud with native replication and by providing a consistent data management platform across both environments. Once in the cloud, customers can take advantage of enterprise-class OneFS features such as multi-protocol support, CloudPools, data reduction, and snapshots, to run their workloads in the same way as they do on-premises. APEX File Storage for AWS can use CloudPools to tier cold or infrequently accessed data to lower cost cloud storage, such as AWS S3 object storage. CloudPools extends the OneFS namespace to the private/public cloud and allows you to store much more data than the usable cluster capacity.
• High performance: APEX File Storage for AWS delivers high-performance file storage with low-latency access to data, ensuring that you can access data quickly and efficiently.

Architecture

The architecture of APEX File Storage for AWS is based on the OneFS distributed file system, which consists of multiple cluster nodes to provide a single global namespace. Each cluster node is an instance of OneFS software that runs on an AWS EC2 instance and provides storage capacity and compute resources. The following diagram shows the architecture of APEX File Storage for AWS.

• Availability zone: APEX File Storage for AWS is designed to run in a single AWS availability zone to get the best performance.
• Virtual Private Cloud (VPC): APEX File Storage for AWS requires an AWS VPC to provide network connectivity.
• OneFS cluster internal subnet: The cluster nodes communicate with each other through the internal subnet. The internal subnet must be isolated from instances that are not in the cluster. Therefore, a dedicated subnet is required for the internal network interfaces of cluster nodes that do not share internal subnets with other EC2 instances.
• OneFS cluster external subnet: The cluster nodes communicate with clients through the external subnet by using different protocols, such as NFS, SMB, and S3.
• OneFS cluster internal network interfaces: Network interfaces that are located in the internal subnet.
• OneFS cluster external network interfaces: Network interfaces that are located in the external subnet.
• OneFS cluster internal security group: The security group applies to the cluster internal network interfaces and allows all traffic between the cluster nodes’ internal network interfaces only.
• OneFS cluster external security group: The security group applies to cluster external network interfaces and allows specific ingress traffic from clients.
• Elastic Compute Cloud (EC2) instance nodes: Cluster nodes that run the OneFS filesystem backed by Elastic Block Store (EBS) volumes and that provide network bandwidth.

 

Supported cluster configuration

APEX File Storage for AWS provides two types of cluster configurations:

• Solid State Drive (SSD) cluster: APEX File Storage for AWS supports clusters backed by General Purpose SSD (gp3) EBS volumes with up to 1PiB cluster raw capacity. The gp3 EBS volumes are the latest generation of General Purpose SSD volumes, and the lowest cost SSD volume offered by AWS EBS. They balance price and performance for a wide variety of workloads.

• Hard Disk Drive (HDD) cluster: APEX File Storage for AWS supports clusters backed by Throughput Optimized HDD (st1) EBS volumes with up to 360TiB cluster raw capacity. The st1 EBS volumes provide low-cost magnetic storage that defines performance in terms of throughput rather than IOPS. This volume type is a good fit for large sequential workloads.

APEX File Storage for AWS can deliver 10GB/s seq read and 4GB/s seq write performance as the cluster size grows. To learn more details about APEX File Storage for AWS, see the following documentation.

• APEX File Storage for AWS Deployment Guide
• APEX File Storage for AWS Overview and Performance
• Interactive Demo

Author: Lieven Lin

In the previous article in this OneFS firewall series, we reviewed the upgrade, activation, and policy selection components of the firewall provisioning process.

Now, we turn our attention to the firewall rule configuration step of the process.

As stated previously, role-based access control (RBAC) explicitly limits who has access to manage the OneFS firewall. So, ensure that the user account that will be used to enable and configure the OneFS firewall belongs to a role with the ‘ISI_PRIV_FIREWALL’ write privilege.

4. Configuring Firewall Rules

When the desired policy is created, the next step is to configure the rules. Clearly, the first step here is to decide which ports and services need securing or opening, beyond the defaults.

The following CLI syntax returns a list of all the firewall’s default services, plus their respective ports, protocols, and aliases, sorted by ascending port number:

# isi network firewall services list
 
Service Name     Port  Protocol   Aliases
 
---------------------------------------------
 
ftp-data         20    TCP        -
 
ftp              21    TCP        -
 
ssh              22    TCP        -
 
smtp             25    TCP        -
 
dns              53    TCP        domain
 
                       UDP
 
http             80    TCP        www
 
                                  www-http
 
kerberos         88    TCP        kerberos-sec
 
                       UDP
 
rpcbind          111   TCP        portmapper
 
                        UDP       sunrpc
 
                                 rpc.bind
 
ntp              123   UDP        -
 
dcerpc           135   TCP        epmap
 
                        UDP       loc-srv
 
netbios-ns       137   UDP        -
 
netbios-dgm      138   UDP        -
 
netbios-ssn      139   UDP        -
 
snmp             161   UDP        -
 
snmptrap         162   UDP        snmp-trap
 
mountd           300   TCP        nfsmountd
 
                       UDP
 
statd            302   TCP        nfsstatd
 
                       UDP
 
lockd            304   TCP       nfslockd
 
                       UDP
 
nfsrquotad       305   TCP        -
 
                       UDP
 
nfsmgmtd         306   TCP        -
 
                       UDP
 
ldap             389   TCP        -
 
                       UDP
 
https            443   TCP        -
 
smb              445   TCP        microsoft-ds
 
hdfs-datanode    585   TCP        -
 
asf-rmcp         623   TCP        -
 
                       UDP
 
ldaps            636   TCP        sldap
 
asf-secure-rmcp  664   TCP        -
 
                       UDP
 
ftps-data        989   TCP        -
 
ftps             990   TCP        -
 
nfs              2049  TCP        nfsd
 
                       UDP
 
tcp-2097         2097  TCP        -
 
tcp-2098         2098  TCP        -
 
tcp-3148         3148  TCP        -
 
tcp-3149         3149  TCP        -
 
tcp-3268         3268  TCP        -
 
tcp-3269         3269  TCP        -
 
tcp-5667         5667  TCP        -
 
tcp-5668         5668  TCP        -
 
isi_ph_rpcd      6557  TCP        -
 
isi_dm_d         7722  TCP        -
 
hdfs-namenode    8020  TCP        -
 
isi_webui        8080  TCP        apache2
 
webhdfs          8082  TCP        -
 
tcp-8083         8083  TCP        -
 
ambari-handshake 8440   TCP       -
 
ambari-heartbeat 8441   TCP       -
 
tcp-8443         8443  TCP        -
 
tcp-8470         8470  TCP        -
 
s3-http          9020  TCP        -
 
s3-https         9021  TCP        -
 
isi_esrs_d       9443  TCP        -
 
ndmp             10000 TCP       -
 
cee              12228 TCP       -
 
nfsrdma          20049 TCP       -
 
                       UDP
 
tcp-28080        28080 TCP       -
 
---------------------------------------------
 
Total: 55

Similarly, the following CLI command generates a list of existing rules and their associated policies, sorted in alphabetical order. For example, to show the first five rules:

# isi network firewall rules list –-limit 5
 
ID                                             Index  Description                                                                              Action
 
----------------------------------------------------------------------------------------------------------------------------------------------------
 
default_pools_policy.rule_ambari_handshake    41      Firewall rule on ambari-handshake service                                                allow
 
default_pools_policy.rule_ambari_heartbeat    42      Firewall rule on ambari-heartbeat service                                               allow
 
default_pools_policy.rule_catalog_search_req  50      Firewall rule on service for global catalog search requests                             allow
 
default_pools_policy.rule_cee                 52     Firewall rule on cee service                                                             allow
 
default_pools_policy.rule_dcerpc_tcp          18      Firewall rule on dcerpc(TCP) service                                                     allow
 
----------------------------------------------------------------------------------------------------------------------------------------------------
 
Total: 5

Both the ‘isi network firewall rules list’ and the ‘isi network firewall services list’ commands also have a ‘-v’ verbose option, and can return their output in csv, list, table, or json formats with the ‘–flag’.

To view the detailed info for a given firewall rule, in this case the default SMB rule, use the following CLI syntax:

# isi network firewall rules view default_pools_policy.rule_smb
 
          ID: default_pools_policy.rule_smb
 
        Name: rule_smb
 
       Index: 3
 
 Description: Firewall rule on smb service
 
    Protocol: TCP
 
   Dst Ports: smb
 
Src Networks: -
 
   Src Ports: -
 
      Action: allow

Existing rules can be modified and new rules created and added into an existing firewall policy with the ‘isi network firewall rules create’ CLI syntax. Command options include:

Note that, unlike for firewall policies, there is no provision for cloning individual rules.

The following CLI syntax can be used to create new firewall rules. For example, to add ‘allow’ rules for the HTTP and SSH protocols, plus a ‘deny’ rule for port TCP 9876, into firewall policy fw_test1:

# isi network firewall rules create  fw_test1.rule_http  --index 1 --dst-ports http --src-networks 10.20.30.0/24,20.30.40.0/24 --action allow
# isi network firewall rules create  fw_test1.rule_ssh  --index 2 --dst-ports ssh --src-networks 10.20.30.0/24,20.30.40.0/16 --action allow
# isi network firewall rules create fw_test1.rule_tcp_9876 --index 3 --protocol tcp --dst-ports 9876   --src-networks 10.20.30.0/24,20.30.40.0/24 -- action deny

When a new rule is created in a policy, if the index value is not specified, it will automatically inherit the next available number in the series (such as index=4 in this case).

# isi network firewall rules create fw_test1.rule_2049  --protocol udp -dst-ports 2049 --src-networks 30.1.0.0/16 -- action deny

For a more draconian approach, a ‘deny’ rule could be created using the match-everything ‘*’ wildcard for destination ports and a 0.0.0.0/0 network and mask, which would silently drop all traffic:

# isi network firewall rules create fw_test1.rule_1234  --index=100--dst-ports * --src-networks 0.0.0.0/0 --action deny

When modifying existing firewall rules, use the following CLI syntax, in this case to change the source network of an HTTP allow rule (index 1) in firewall policy fw_test1:

# isi network firewall rules modify fw_test1.rule_http --index 1  --protocol ip --dst-ports http --src-networks 10.1.0.0/16 -- action allow

Or to modify an SSH rule (index 2) in firewall policy fw_test1, changing the action from ‘allow’ to ‘deny’:

# isi network firewall rules modify fw_test1.rule_ssh --index 2 --protocol tcp --dst-ports ssh --src-networks 10.1.0.0/16,20.2.0.0/16 -- action deny

Also, to re-order the custom TCP 9876 rule form the earlier example from index 3 to index 7 in firewall policy fw_test1.

# isi network firewall rules modify fw_test1.rule_tcp_9876 --index 7

Note that all rules equal or behind index 7 will have their index values incremented by one.

When deleting a rule from a firewall policy, any rule reordering is handled automatically. If the policy has been applied to a network pool, the ‘–live’ option can be used to force the change to take effect immediately. For example, to delete the HTTP rule from the firewall policy ‘fw_test1’:

# isi network firewall policies delete fw_test1.rule_http --live

Firewall rules can also be created, modified, and deleted within a policy from the WebUI by navigating to Cluster management > Firewall Configuration > Firewall Policies. For example, to create a rule that permits SupportAssist and Secure Gateway traffic on the 10.219.0.0/16 network:

Once saved, the new rule is then displayed in the Firewall Configuration page:

5. Firewall management and monitoring.

In the next and final article in this series, we’ll turn our attention to managing, monitoring, and troubleshooting the OneFS firewall (Step 5).

Author: Nick Trimbee

The new firewall in OneFS 9.5 enhances the security of the cluster and helps prevent unauthorized access to the storage system. When enabled, the default firewall configuration allows remote systems access to a specific set of default services for data, management, and inter-cluster interfaces (network pools).

The basic OneFS firewall provisioning process is as follows:

Note that role-based access control (RBAC) explicitly limits who has access to manage the OneFS firewall. In addition to the ubiquitous root, the cluster’s built-in SystemAdmin role has write privileges to configure and administer the firewall.

1.  Upgrade cluster to OneFS 9.5.

First, to provision the firewall, the cluster must be running OneFS 9.5.

If you are upgrading from an earlier release, the OneFS 9.5 upgrade must be committed before enabling the firewall.

Also, be aware that configuration and management of the firewall in OneFS 9.5 requires the new ISI_PRIV_FIREWALL administration privilege. 

# isi auth privilege | grep -i firewall
ISI_PRIV_FIREWALL                   Configure network firewall

This privilege can be granted to a role with either read-only or read/write permissions. By default, the built-in SystemAdmin role is granted write privileges to administer the firewall:

# isi auth roles view SystemAdmin | grep -A2 -i firewall
             ID: ISI_PRIV_FIREWALL
     Permission: w

Additionally, the built-in AuditAdmin role has read permission to view the firewall configuration and logs, and so on:

# isi auth roles view AuditAdmin | grep -A2 -i firewall
             ID: ISI_PRIV_FIREWALL
     Permission: r

Ensure that the user account that will be used to enable and configure the OneFS firewall belongs to a role with the ISI_PRIV_FIREWALL write privilege.

2.  Activate firewall.

The OneFS firewall can be either enabled or disabled, with the latter as the default state. 

The following CLI syntax will display the firewall’s global status (in this case disabled, the default):

# isi network firewall settings view
Enabled: False

Firewall activation can be easily performed from the CLI as follows:

# isi network firewall settings modify --enabled true
# isi network firewall settings view
Enabled: True

Or from the WebUI under Cluster management > Firewall Configuration > Settings:

Note that the firewall is automatically enabled when STIG hardening is applied to a cluster.

3.  Select policies.

A cluster’s existing firewall policies can be easily viewed from the CLI with the following command:

# isi network firewall policies list
ID        Pools                    Subnets                   Rules
 -----------------------------------------------------------------------------
 fw_test1  groupnet0.subnet0.pool0  groupnet0.subnet1         test_rule1
 -----------------------------------------------------------------------------
 Total: 1

Or from the WebUI under Cluster management > Firewall Configuration > Firewall Policies:

The OneFS firewall offers four main strategies when it comes to selecting a firewall policy: 

1. Retaining the default policy
2. Reconfiguring the default policy
3. Cloning the default policy and reconfiguring
4. Creating a custom firewall policy

We’ll consider each of these strategies in order:

a.  Retaining the default policy

In many cases, the default OneFS firewall policy value provides acceptable protection for a security-conscious organization. In these instances, once the OneFS firewall has been enabled on a cluster, no further configuration is required, and the cluster administrators can move on to the management and monitoring phase.

The firewall policy for all front-end cluster interfaces (network pool) is the default. While the default policy can be modified, be aware that this default policy is global. As such, any change against it will affect all network pools using this default policy.

The following table describes the default firewall policies that are assigned to each interface:

These can be viewed from the CLI as follows:

# isi network firewall policies view default_pools_policy
            ID: default_pools_policy
          Name: default_pools_policy
    Description: Default Firewall Pools Policy
Default Action: deny
      Max Rules: 100
          Pools: groupnet0.subnet0.pool0, groupnet0.subnet0.testpool1, groupnet0.subnet0.testpool2, groupnet0.subnet0.testpool3, groupnet0.subnet0.testpool4, groupnet0.subnet0.poolcava
        Subnets: -
          Rules: rule_ldap_tcp, rule_ldap_udp, rule_reserved_for_hw_tcp, rule_reserved_for_hw_udp, rule_isi_SyncIQ, rule_catalog_search_req, rule_lwswift, rule_session_transfer, rule_s3, rule_nfs_tcp, rule_nfs_udp, rule_smb, rule_hdfs_datanode, rule_nfsrdma_tcp, rule_nfsrdma_udp, rule_ftp_data, rule_ftps_data, rule_ftp, rule_ssh, rule_smtp, rule_http, rule_kerberos_tcp, rule_kerberos_udp, rule_rpcbind_tcp, rule_rpcbind_udp, rule_ntp, rule_dcerpc_tcp, rule_dcerpc_udp, rule_netbios_ns, rule_netbios_dgm, rule_netbios_ssn, rule_snmp, rule_snmptrap, rule_mountd_tcp, rule_mountd_udp, rule_statd_tcp, rule_statd_udp, rule_lockd_tcp, rule_lockd_udp, rule_nfsrquotad_tcp, rule_nfsrquotad_udp, rule_nfsmgmtd_tcp, rule_nfsmgmtd_udp, rule_https, rule_ldaps, rule_ftps, rule_hdfs_namenode, rule_isi_webui, rule_webhdfs, rule_ambari_handshake, rule_ambari_heartbeat, rule_isi_esrs_d, rule_ndmp, rule_isi_ph_rpcd, rule_cee, rule_icmp, rule_icmp6, rule_isi_dm_d

 # isi network firewall policies view default_subnets_policy
            ID: default_subnets_policy
          Name: default_subnets_policy
    Description: Default Firewall Subnets Policy
Default Action: deny
      Max Rules: 100
          Pools: -
        Subnets: groupnet0.subnet0
          Rules: rule_subnets_dns_tcp, rule_subnets_dns_udp, rule_icmp, rule_icmp6

Or from the WebUI under Cluster management > Firewall Configuration > Firewall Policies:

b.  Reconfiguring the default policy

Depending on an organization’s threat levels or security mandates, there may be a need to restrict access to certain additional IP addresses and/or management service protocols.

If the default policy is deemed insufficient, reconfiguring the default firewall policy can be a good option if only a small number of rule changes are required. The specifics of creating, modifying, and deleting individual firewall rules is covered later in this article (step 3).

Note that if new rule changes behave unexpectedly, or firewall configuration generally goes awry, OneFS does provide a “get out of jail free” card. In a pinch, the global firewall policy can be quickly and easily restored to its default values. This can be achieved with the following CLI syntax:

# isi network firewall reset-global-policy

This command will reset the global firewall policies to the original system defaults. Are you sure you want to continue? (yes/[no]):

Alternatively, the default policy can also be easily reverted from the WebUI by clicking the Reset default policies:

 c.  Cloning the default policy and reconfiguring

Another option is cloning, which can be useful when batch modification or a large number of changes to the current policy are required. By cloning the default firewall policy, an exact copy of the existing policy and its rules is generated, but with a new policy name. For example:

# isi network firewall policies clone default_pools_policy clone_default_pools_policy
# isi network firewall policies list | grep -i clone
clone_default_pools_policy -                           

Cloning can also be initiated from the WebUI under Firewall Configuration > Firewall Policies > More Actions > Clone Policy:

Enter a name for the clone in the Policy Name field in the pop-up window, and click Save:

 Once cloned, the policy can then be easily reconfigured to suit. For example, to modify the policy fw_test1 and change its default-action from deny-all to allow-all:

# isi network firewall policies modify fw_test1 --default-action allow-all

When modifying a firewall policy, you can use the --live CLI option to force it to take effect immediately. Note that the --live option is only valid when issuing a command to modify or delete an active custom policy and to modify default policy. Such changes will take effect immediately on all network subnets and pools associated with this policy. Using the --live option on an inactive policy will be rejected, and an error message returned.

Options for creating or modifying a firewall policy include:

When you modify firewall policies, OneFS issues the following warning to verify the changes and help avoid the risk of a self-induced denial-of-service:   

# isi network firewall policies modify --pools groupnet0.subnet0.pool0 fw_test1

Changing the Firewall Policy associated with a subnet or pool may change the networks and/or services allowed to connect to OneFS. Please confirm you have selected the correct Firewall Policy and Subnets/Pools. Are you sure you want to continue? (yes/[no]): yes

Once again, having the following CLI command handy, plus console access to the cluster is always a prudent move:

# isi network firewall reset-global-policy

So adding network pools or subnets to a firewall policy will cause the previous policy to be removed from them. Similarly, adding network pools or subnets to the global default policy will revert any custom policy configuration they might have. For example, to apply the firewall policy fw_test1 to IP Pool groupnet0.subnet0.pool0 and groupnet0.subnet0.pool1:

# isi network pools view groupnet0.subnet0.pool0 | grep -i firewall
       Firewall Policy: default_pools_policy
# isi network firewall policies modify fw_test1 --add-pools groupnet0.subnet0.pool0, groupnet0.subnet0.pool1
# isi network pools view groupnet0.subnet0.pool0 | grep -i firewall
       Firewall Policy: fw_test1

Or to apply the firewall policy fw_test1 to IP Pool groupnet0.subnet0.pool0 and groupnet0.subnet0:

# isi network firewall policies modify fw_test1 --apply-subnet groupnet0.subnet0.pool0, groupnet0.subnet0
# isi network pools view groupnet0.subnet0.pool0 | grep -i firewall
 Firewall Policy: fw_test1
# isi network subnets view groupnet0.subnet0 | grep -i firewall
 Firewall Policy: fw_test1

To reapply global policy at any time, either add the pools to the default policy:

# isi network firewall policies modify default_pools_policy --add-pools groupnet0.subnet0.pool0, groupnet0.subnet0.pool1
# isi network pools view groupnet0.subnet0.pool0 | grep -i firewall
 Firewall Policy: default_subnets_policy
# isi network subnets view groupnet0.subnet1 | grep -i firewall
 Firewall Policy: default_subnets_policy

Or remove the pool from the custom policy:

# isi network firewall policies modify fw_test1 --remove-pools groupnet0.subnet0.pool0 groupnet0.subnet0.pool1

You can also manage firewall policies on a network pool in the OneFS WebUI by going to Cluster configuration > Network configuration > External network > Edit pool details. For example:

Be aware that cloning is also not limited to the default policy because clones can be made of any custom policies too. For example:

# isi network firewall policies clone clone_default_pools_policy fw_test1

d.  Creating a custom firewall policy

Alternatively, a custom firewall policy can also be created from scratch. This can be accomplished from the CLI using the following syntax, in this case to create a firewall policy named fw_test1:

# isi network firewall policies create fw_test1 --default-action deny
# isi network firewall policies view fw_test1
            ID: fw_test1
          Name: fw_test1
    Description:
Default Action: deny
      Max Rules: 100
          Pools: -
        Subnets: -
          Rules: -

Note that if a default-action is not specified in the CLI command syntax, it will automatically default to deny.

Firewall policies can also be configured in the OneFS WebUI by going to Cluster management > Firewall Configuration > Firewall Policies > Create Policy:

However, in contrast to the CLI, if a default-action is not specified when a policy is created in the WebUI, the automatic default is to Allow because the drop-down list works alphabetically.

If and when a firewall policy is no longer required, it can be swiftly and easily removed. For example, the following CLI syntax deletes the firewall policy fw_test1, clearing out any rules within this policy container:

# isi network firewall policies delete fw_test1
Are you sure you want to delete firewall policy fw_test1? (yes/[no]): yes

Note that the default global policies cannot be deleted.

# isi network firewall policies delete default_subnets_policy
Are you sure you want to delete firewall policy default_subnets_policy? (yes/[no]): yes
Firewall policy: Cannot delete default policy default_subnets_policy.

4.  Configure firewall rules.

 In the next article in this series, we’ll turn our attention to this step, configuring the OneFS firewall rules.

Among the array of security features introduced in OneFS 9.5 is a new host-based firewall. This firewall allows cluster administrators to configure policies and rules on a PowerScale cluster in order to meet the network and application management needs and security mandates of an organization.

The OneFS firewall protects the cluster’s external, or front-end, network and operates as a packet filter for inbound traffic. It is available upon installation or upgrade to OneFS 9.5 but is disabled by default in both cases. However, the OneFS STIG hardening profile automatically enables the firewall and the default policies, in addition to manual activation.

The firewall generally manages IP packet filtering in accordance with the OneFS Security Configuration Guide, especially in regards to the network port usage. Packet control is governed by firewall policies, which have one or more individual rules.

 A security best practice is to enable the OneFS firewall using the default policies, with any adjustments as required. The recommended configuration process is as follows:

Under the hood, the OneFS firewall is built upon the ubiquitous ipfirewall, or ipfw, which is FreeBSD’s native stateful firewall, packet filter, and traffic accounting facility.

Firewall configuration and management is through the CLI, or platform API, or WebUI, and OneFS 9.5 introduces a new Firewall Configuration page to support this. Note that the firewall is only available once a cluster is already running OneFS 9.5 and the feature has been manually enabled, activating the isi_firewall_d service. The firewall’s configuration is split between gconfig, which handles the settings and policies, and the ipfw table, which stores the rules themselves.

The firewall gracefully handles SmartConnect dynamic IP movement between nodes since firewall policies are applied per network pool. Additionally, being network pool based allows the firewall to support OneFS access zones and shared/multitenancy models. 

The individual firewall rules, which are essentially simplified wrappers around ipfw rules, work by matching packets through the 5-tuples that uniquely identify an IPv4 UDP or TCP session:

• Source IP address
• Source port
• Destination IP address
• Destination port
• Transport protocol

The rules are then organized within a firewall policy, which can be applied to one or more network pools. 

Note that each pool can only have a single firewall policy applied to it. If there is no custom firewall policy configured for a network pool, it automatically uses the global default firewall policy.

When enabled, the OneFS firewall function is cluster wide, and all inbound packets from external interfaces will go through either the custom policy or default global policy before reaching the protocol handling pathways. Packets passed to the firewall are compared against each of the rules in the policy, in rule-number order. Multiple rules with the same number are permitted, in which case they are processed in order of insertion. When a match is found, the action corresponding to that matching rule is performed. A packet is checked against the active ruleset in multiple places in the protocol stack, and the basic flow is as follows: 

1. Get the logical interface for incoming packets.
2. Find all network pools assigned to this interface.
3. Compare these network pools one by one with destination IP address to find the matching pool (either custom firewall policy, or default global policy).
4. Compare each rule with service (protocol and destination ports) and source IP address in this pool in order of lowest index value.  If matched, perform actions according to the associated rule.
5. If no rule matches, go to the final rule (deny all or allow all), which is specified upon policy creation.

The OneFS firewall automatically reserves 20,000 rules in the ipfw table for its custom and default policies and rules. By default, each policy can have a maximum of 100 rules, including one default rule. This translates to an effective maximum of 99 user-defined rules per policy, because the default rule is reserved and cannot be modified. As such, a maximum of 198 policies can be applied to pools or subnets since the default-pools-policy and default-subnets-policy are reserved and cannot be deleted.

Additional firewall bounds and limits to keep in mind include:

The firewall default global policy is ready to use out of the box and, unless a custom policy has been explicitly configured, all network pools use this global policy. Custom policies can be configured by either cloning and modifying an existing policy or creating one from scratch. 

For a given network pool, either the global policy or a custom policy is assigned and takes effect. Additionally, all configuration changes to either policy type are managed by gconfig and are persistent across cluster reboots.

In the next article in this series we’ll take a look at the CLI and WebUI configuration and management of the OneFS firewall. 

In this era of elevated cyber-crime and data security threats, there is increasing demand for immutable, tamper-proof snapshots. Often this need arises as part of a broader security mandate, ideally proactively, but oftentimes as a response to a security incident. OneFS addresses this requirement in the following ways:

Read-only snapshots

At its core, OneFS SnapshotIQ generates read-only, point-in-time, space efficient copies of a defined subset of a cluster’s data.

Only the changed blocks of a file are stored when updating OneFS snapshots, ensuring efficient storage utilization. They are also highly scalable and typically take less than a second to create, while generating little performance overhead. As such, the RPO (recovery point objective) and RTO (recovery time objective) of a OneFS snapshot can be very small and highly flexible, with the use of rich policies and schedules.

OneFS Snapshots are created manually, on a schedule, or automatically generated by OneFS to facilitate system operations. But whatever the generation method, when a snapshot has been taken, its contents cannot be manually altered.

Snapshot Locks

In addition to snapshot contents immutability, for an enhanced level of tamper-proofing, SnapshotIQ also provides the ability to lock snapshots with the ‘isi snapshot locks’ CLI syntax. This prevents snapshots from being accidentally or unintentionally deleted.

For example, a manual snapshot, ‘snaploc1’ is taken of /ifs/test:

# isi snapshot snapshots create /ifs/test --name snaploc1
# isi snapshot snapshots list | grep snaploc1
79188 snaploc1                                     /ifs/test

A lock is then placed on it (in this case lock ID=1):

# isi snapshot locks create snaplock1
# isi snapshot locks list snaploc1
ID
----
1
----
Total: 1

Attempts to delete the snapshot fail because the lock prevents its removal:

# isi snapshot snapshots delete snaploc1
Are you sure? (yes/[no]): yes
Snapshot "snaploc1" can't be deleted because it is locked

The CLI command ‘isi snapshot locks delete <lock_ID>’ can be used to clear existing snapshot locks, if desired. For example, to remove the only lock (ID=1) from snapshot ‘snaploc1’:

# isi snapshot locks list snaploc1
ID
----
1
----
Total: 1
# isi snapshot locks delete snaploc1 1
Are you sure you want to delete snapshot lock 1 from snaploc1? (yes/[no]): yes
# isi snap locks view snaploc1 1
No such lock

When the lock is removed, the snapshot can then be deleted:

# isi snapshot snapshots delete snaploc1
Are you sure? (yes/[no]): yes
# isi snapshot snapshots list| grep -i snaploc1 | wc -l
       0

Note that a snapshot can have up to a maximum of sixteen locks on it at any time. Also, lock numbers are continually incremented and not recycled upon deletion.

Like snapshot expiration, snapshot locks can also have an expiration time configured. For example, to set a lock on snapshot ‘snaploc1’ that expires at 1am on April 1st, 2024:

# isi snap lock create snaploc1 --expires '2024-04-01T01:00:00'
# isi snap lock list snaploc1
ID
----
36
----
Total: 1
# isi snap lock view snaploc1 33
     ID: 36
Comment:
Expires: 2024-04-01T01:00:00
  Count: 1

Note that if the duration period of a particular snapshot lock expires but others remain, OneFS will not delete that snapshot until all the locks on it have been deleted or expired.

The following table provides an example snapshot expiration schedule, with monthly locked snapshots to prevent deletion:

Roles-based Access Control

Read-only snapshots plus locks present physically secure snapshots on a cluster. However, if you can login to the cluster and have the required elevated administrator privileges to do so, you can still remove locks and/or delete snapshots.

Because data security threats come from inside an environment as well as out, such as from a disgruntled IT employee or other internal bad actor, another key to a robust security profile is to constrain the use of all-powerful ‘root’, ‘administrator’, and ‘sudo’ accounts as much as possible. Instead, of granting cluster admins full rights, a preferred security best practice is to leverage the comprehensive authentication, authorization, and accounting framework that OneFS natively provides.

OneFS role-based access control (RBAC) can be used to explicitly limit who has access to manage and delete snapshots. This granular control allows you to craft administrative roles that can create and manage snapshot schedules, but prevent their unlocking and/or deletion. Similarly, lock removal and snapshot deletion can be isolated to a specific security role (or to root only).

A cluster security administrator selects the desired access zone, creates a zone-aware role within it, assigns privileges, and then assigns members.

For example, from the WebUI under Access > Membership and roles > Roles:

When these members access the cluster through the WebUI, PlatformAPI, or CLI, they inherit their assigned privileges.

The specific privileges that can be used to segment OneFS snapshot management include:

Each privilege can be assigned one of four permission levels for a role, including:

The ability for a user to delete a snapshot is governed by the ‘ISI_PRIV_SNAPSHOT_SNAPSHOTMANAGEMENT’ privilege. Similarly, the ‘ISI_PRIV_SNAPSHOT_LOCKS’ privilege governs lock creation and removal.

In the following example, the ‘snap’ role has ‘read’ rights for the ‘ISI_PRIV_SNAPSHOT_LOCKS’ privilege, allowing a user associated with this role to view snapshot locks:

# isi auth roles view snap | grep -I -A 1 locks
             ID: ISI_PRIV_SNAPSHOT_LOCKS
     Permission: r
--
# isi snapshot locks list snaploc1
ID
----
1
----
Total: 1

However, attempts to remove the lock ‘ID 1’ from the ‘snaploc1’ snapshot fail without write privileges:

# isi snapshot locks delete snaploc1 1
Privilege check failed. The following write privilege is required: Snapshot locks (ISI_PRIV_SNAPSHOT_LOCKS)

Write privileges are added to ‘ISI_PRIV_SNAPSHOT_LOCKS’ in the ‘’snaploc1’ role:

# isi auth roles modify snap –-add-priv-write ISI_PRIV_SNAPSHOT_LOCKS
# isi auth roles view snap | grep -I -A 1 locks
             ID: ISI_PRIV_SNAPSHOT_LOCKS
     Permission: w
--

This allows the lock ‘ID 1’ to be successfully deleted from the ‘snaploc1’ snapshot:

# isi snapshot locks delete snaploc1 1
Are you sure you want to delete snapshot lock 1 from snaploc1? (yes/[no]): yes
# isi snap locks view snaploc1 1
No such lock

Using OneFS RBAC, an enhanced security approach for a site could be to create three OneFS roles on a cluster, each with an increasing realm of trust:

1.  First, an IT ops/helpdesk role with ‘read’ access to the snapshot attributes would permit monitoring and troubleshooting, but no changes:

2.  Next, a cluster admin role, with ‘read’ privileges for ‘ISI_PRIV_SNAPSHOT_LOCKS’ and ‘ISI_PRIV_SNAPSHOT_SNAPSHOTMANAGEMENT’ would prevent snapshot and lock deletion, but provide ‘write’ access for schedule configuration, restores, and so on.

3.  Finally, a cluster security admin role (root equivalence) would provide full snapshot configuration and management, lock control, and deletion rights:

Note that when configuring OneFS RBAC, remember to remove the ‘ISI_PRIV_AUTH’ and ‘ISI_PRIV_ROLE’ privilege from all but the most trusted administrators.

Additionally, enterprise security management tools such as CyberArk can also be incorporated to manage authentication and access control holistically across an environment. These can be configured to frequently change passwords on trusted accounts (that is, every hour or so), require multi-Level approvals prior to retrieving passwords, and track and audit password requests and trends.

While this article focuses exclusively on OneFS snapshots, the expanded use of RBAC granular privileges for enhanced security is germane to most key areas of cluster management and data protection, such as SyncIQ replication, and so on.

Snapshot replication

In addition to using snapshots for its own checkpointing system, SyncIQ, the OneFS data replication engine, supports snapshot replication to a target cluster.

OneFS SyncIQ replication policies contain an option for triggering a replication policy when a snapshot of the source directory is completed. Additionally, at the onset of a new policy configuration, when the “Whenever a Snapshot of the Source Directory is Taken” option is selected, a checkbox appears to enable any existing snapshots in the source directory to be replicated. More information is available in this SyncIQ paper.

Cyber-vaulting

File data is arguably the most difficult to protect, because:

• It is the only type of data where potentially all employees have a direct connection to the storage (with the other type of storage it’s through an application)
• File data is linked (or mounted) to the operating system of the client. This means that it’s sufficient to gain file access to the OS to get access to potentially critical data.
• Users are the largest breach points.

The Cyber Security Framework (CSF) from the National Institute of Standards and Technology (NIST) categorizes the threat through recovery process:

Within the ‘Protect’ phase, there are two core aspects:

• Applying all the core protection features available on the OneFS platform, namely:

• Data isolation provides a last resort copy of business critical data, and can be achieved by using an air gap to isolate the cyber vault copy of the data. The vault copy is logically separated from the production copy of the data. Data syncing happens only intermittently by closing the air gap after ensuring that there are no known issues.

The combination of OneFS snapshots and SyncIQ replication allows for granular data recovery. This means that only the affected files are recovered, while the most recent changes are preserved for the unaffected data. While an on-prem air-gapped cyber vault can still provide secure network isolation, in the event of an attack, the ability to failover to a fully operational ‘clean slate’ remote site provides additional security and peace of mind.

We’ll explore PowerScale cyber protection and recovery in more depth in a future article.

Author: Nick Trimbee

The previous article in this series looked at an overview of OneFS SupportAssist. Now, we’ll turn our attention to its core architecture and operation.

Under the hood, SupportAssist relies on the following infrastructure and services:

Of these, ESE, isi_crispies_d, isi_rice_d, and the Transaction Journal are new in OneFS 9.5 and exclusive to SupportAssist. By contrast, Gconfig, MCP, and Tardis are all legacy services that are used by multiple other OneFS components.

The Remote Information Connectivity Engine (RICE) represents the new SupportAssist ecosystem for OneFS to connect to the Dell backend. The high level architecture is as follows:

Dell’s Embedded Service Enabler (ESE) is at the core of the connectivity platform and acts as a unified communications broker between the PowerScale cluster and Dell Support. ESE runs as a OneFS service and, on startup, looks for an on-premises gateway server. If none is found, it connects back to the connectivity pipe (SRS). The collector service then interacts with ESE to send telemetry, obtain upgrade packages, transmit alerts and events, and so on.

Depending on the available resources, ESE provides a base functionality with additional optional capabilities to enhance serviceability. ESE is multithreaded, and each payload type is handled by specific threads. For example, events are handled by event threads, binary and structured payloads are handled by web threads, and so on. Within OneFS, ESE gets installed to /usr/local/ese and runs as ‘ese’ user and group.

The responsibilities of isi_rice_d include listening for network changes, getting eligible nodes elected for communication, monitoring notifications from CRISPIES, and engaging Task Manager when ESE is ready to go.

The Task Manager is a core component of the RICE engine. Its responsibility is to watch the incoming tasks that are placed into the journal and to assign workers to step through the tasks  until completion. It controls the resource utilization (Python threads) and distributes tasks that are waiting on a priority basis.

The ‘isi_crispies_d’ service exists to ensure that ESE is only running on the RICE active node, and nowhere else. It acts, in effect, like a specialized MCP just for ESE and RICE-associated services, such as IPA. This entails starting ESE on the RICE active node, re-starting it if it crashes on the RICE active node, and stopping it and restarting it on the appropriate node if the RICE active instance moves to another node. We are using ‘isi_crispies_d’ for this, and not MCP, because MCP does not support a service running on only one node at a time.

The core responsibilities of ‘isi_crispies_d’ include:

• Starting and stopping ESE on the RICE active node
• Monitoring ESE and restarting, if necessary. ‘isi_crispies_d’ restarts ESE on the node if it crashes. It will retry a couple of times and then notify RICE if it’s unable to start ESE.
• Listening for gconfig changes and updating ESE. Stopping ESE if unable to make a change and notifying RICE.
• Monitoring other related services.

The state of ESE, and of other RICE service peripherals, is stored in the OneFS tardis configuration database so that it can be checked by RICE. Similarly, ‘isi_crispies_d’ monitors the OneFS Tardis configuration database to see which node is designated as the RICE ‘active’ node.

The ‘isi_telemetry_d’ daemon is started by MCP and runs when SupportAssist is enabled. It does not have to be running on the same node as the active RICE and ESE instance. Only one instance of ‘isi_telemetry_d’ will be active at any time, and the other nodes will be waiting for the lock.

You can query the current status and setup of SupportAssist on a PowerScale cluster by using the ‘isi supportassist settings view’ CLI command. For example:

# isi supportassist settings view
        Service enabled: Yes
       Connection State: enabled
      OneFS Software ID: ELMISL08224764
          Network Pools: subnet0:pool0
        Connection mode: direct
           Gateway host: -
           Gateway port: -
    Backup Gateway host: -
    Backup Gateway port: -
  Enable Remote Support: Yes
Automatic Case Creation: Yes
       Download enabled: Yes

You can also do this from the WebUI by navigating to Cluster management > General settings > SupportAssist:

You can enable or disable SupportAssist by using the ‘isi services’ CLI command set. For example:

# isi services isi_supportassist disable
The service 'isi_supportassist' has been disabled.
# isi services isi_supportassist enable
The service 'isi_supportassist' has been enabled.
# isi services -a | grep supportassist
   isi_supportassist    SupportAssist Monitor                    Enabled

You can check the core services, as follows:

# ps -auxw | grep -e 'rice' -e 'crispies' | grep -v grep
root    8348    9.4   0.0 109844  60984  -   Ss   22:14        0:00.06 /usr/libexec/isilon/isi_crispies_d /usr/bin/isi_crispies_d
root    8183    8.8   0.0 108060  64396  -   Ss   22:14        0:01.58 /usr/libexec/isilon/isi_rice_d /usr/bin/isi_rice_d

Note that when a cluster is provisioned with SupportAssist, ESRS can no longer be used. However, customers that have not previously connected their clusters to Dell Support can still provision ESRS, but will be presented with a message encouraging them to adopt the best practice of using SupportAssist.

Additionally, SupportAssist in OneFS 9.5 does not currently support IPv6 networking, so clusters deployed in IPv6 environments should continue to use ESRS until SupportAssist IPv6 integration is introduced in a future OneFS release.

Author: Nick Trimbee

In this final article in the OneFS SupportAssist series, we turn our attention to management and troubleshooting.

Once the provisioning process above is complete, the isi supportassist settings view CLI command reports the status and health of SupportAssist operations on the cluster.

# isi supportassist settings view
        Service enabled: Yes
       Connection State: enabled
      OneFS Software ID: xxxxxxxxxx
          Network Pools: subnet0:pool0
        Connection mode: direct
           Gateway host: -
           Gateway port: -
    Backup Gateway host: -
    Backup Gateway port: -
  Enable Remote Support: Yes
Automatic Case Creation: Yes
       Download enabled: Yes

This can also be obtained from the WebUI by going to Cluster management > General settings > SupportAssist:

 There are some caveats and considerations to keep in mind when upgrading to OneFS 9.5 and enabling SupportAssist, including:

• SupportAssist is disabled when STIG hardening is applied to a cluster.
• Using SupportAssist on a hardened cluster is not supported.
• Clusters with the OneFS network firewall enabled (isi network firewall settings) might need to allow outbound traffic on port 9443.
• SupportAssist is supported on a cluster that’s running in Compliance mode.
• Secure keys are held in key manager under the RICE domain.

Also, note that Secure Remote Services can no longer be used after SupportAssist has been provisioned on a cluster.

SupportAssist has a variety of components that gather and transmit various pieces of OneFS data and telemetry to Dell Support and backend services through the Embedded Service Enabler (ESE). These workflows include CELOG events; in-product activation (IPA) information; CloudIQ telemetry data; Isi-Gather-info (IGI) logsets; and provisioning, configuration, and authentication data to ESE and the various backend services.

CELOG

Once SupportAssist is up and running, it can be configured to send CELOG events and attachments  through ESE to CLM. This can be managed by the isi event channels CLI command syntax. For example:

# isi event channels list
ID   Name                Type          Enabled
-----------------------------------------------
1    RemoteSupport       connectemc    No
2    Heartbeat Self-Test heartbeat     Yes
3    SupportAssist       supportassist No
-----------------------------------------------
Total: 3
# isi event channels view SupportAssist
     ID: 3
   Name: SupportAssist
   Type: supportassist
Enabled: No

Or from the WebUI:

CloudIQ telemetry

In OneFS 9.5, SupportAssist provides an option to send telemetry data to CloudIQ. This can be enabled from the CLI as follows:

# isi supportassist telemetry modify --telemetry-enabled 1 --telemetry-persist 0
# isi supportassist telemetry view
        Telemetry Enabled: Yes
        Telemetry Persist: No
        Telemetry Threads: 8
Offline Collection Period: 7200

Or in the SupportAssist WebUI:

Diagnostics gather

Also in OneFS 9.5, the isi diagnostics gather and isi_gather_info CLI commands both include a --supportassist upload option for log gathers, which also allows them to continue to function through a new “emergency mode” when the cluster is unhealthy. For example, to start a gather from the CLI that will be uploaded through SupportAssist:

# isi diagnostics gather start –supportassist 1

Similarly, for ISI gather info:

# isi_gather_info --supportassist

Or to explicitly avoid using SupportAssist for ISI gather info log gather upload:

# isi_gather_info --nosupportassist

This can also be configured from the WebUI at Cluster management > General configuration > Diagnostics > Gather:

License Activation through SupportAssist

PowerScale License Activation (previously known as In-Product Activation) facilitates the management of the cluster's entitlements and licenses by communicating directly with Software Licensing Central through SupportAssist.

To activate OneFS product licenses through the SupportAssist WebUI:

1. Go to Cluster management > Licensing. 
   For example, on a new cluster without any signed licenses:
   
   
    
2. Click the Update & Refresh button in the License Activation section. In the Activation File Wizard, select the software modules that you want in the activation file.
   
    
   
   
3. Select Review changes, review, click Proceed, and finally Activate

Note that it can take up to 24 hours for the activation to occur.

Alternatively, cluster license activation codes (LAC) can also be added manually.

Troubleshooting

When it comes to troubleshooting SupportAssist, the basic process flow is as follows:

 
The OneFS components and services above are:

Of these, ESE, isi_crispies_d, isi_rice_d, and the transaction journal are new in OneFS 9.5 and exclusive to SupportAssist. In contrast, Gconfig, MCP, and Tardis are all legacy services that are used by multiple other OneFS components. 

For its connectivity, SupportAssist elects a single leader single node within the subnet pool, and NANON nodes are automatically avoided. Ports 443 and 8443 are required to be open for bi-directional communication between the cluster and Connectivity Hub, and port 9443 is for communicating with a gateway. The SupportAssist ESE component communicates with a number of Dell backend services:

• SRS
• Connectivity Hub
• CLM
• ELMS/Licensing
• SDR
• Lightning
• Log Processor
• CloudIQ
• ESE

Debugging backend issues might involve one or more services, and Dell Support can assist with this process.

The main log files for investigating and troubleshooting SupportAssist issues and idiosyncrasies are isi_rice_d.log and isi_crispies_d.log. There is also an ese_log, which can be useful, too. These logs can be found at:

Debug level logging can be configured from the CLI as follows:

# isi_for_array isi_ilog -a isi_crispies_d --level=debug+
# isi_for_array isi_ilog -a isi_rice_d --level=debug+

Note that the OneFS log gathers (such as the output from the isi_gather_info utility) will capture all the above log files, plus the pertinent SupportAssist Gconfig contexts and Tardis namespaces, for later analysis.

If needed, the Rice and ESE configurations can also be viewed as follows:

# isi_gconfig -t ese
[root] {version:1}
ese.mode (char*) = direct
ese.connection_state (char*) = disabled
ese.enable_remote_support (bool) = true
ese.automatic_case_creation (bool) = true
ese.event_muted (bool) = false
ese.primary_contact.first_name (char*) =
ese.primary_contact.last_name (char*) =
ese.primary_contact.email (char*) =
ese.primary_contact.phone (char*) =
ese.primary_contact.language (char*) =
ese.secondary_contact.first_name (char*) =
ese.secondary_contact.last_name (char*) =
ese.secondary_contact.email (char*) =
ese.secondary_contact.phone (char*) =
ese.secondary_contact.language (char*) =
(empty dir ese.gateway_endpoints)
ese.defaultBackendType (char*) = srs
ese.ipAddress (char*) = 127.0.0.1
ese.useSSL (bool) = true
ese.srsPrefix (char*) = /esrs/{version}/devices
ese.directEndpointsUseProxy (bool) = false
ese.enableDataItemApi (bool) = true
ese.usingBuiltinConfig (bool) = false
ese.productFrontendPrefix (char*) = platform/16/supportassist
ese.productFrontendType (char*) = webrest
ese.contractVersion (char*) = 1.0
ese.systemMode (char*) = normal
ese.srsTransferType (char*) = ISILON-GW
ese.targetEnvironment (char*) = PROD
 
# isi_gconfig -t rice
[root] {version:1}
rice.enabled (bool) = false
rice.ese_provisioned (bool) = false
rice.hardware_key_present (bool) = false
rice.supportassist_dismissed (bool) = false
rice.eligible_lnns (char*) = []
rice.instance_swid (char*) =
rice.task_prune_interval (int) = 86400
rice.last_task_prune_time (uint) = 0
rice.event_prune_max_items (int) = 100
rice.event_prune_days_to_keep (int) = 30
rice.jnl_tasks_prune_max_items (int) = 100
rice.jnl_tasks_prune_days_to_keep (int) = 30
rice.config_reserved_workers (int) = 1
rice.event_reserved_workers (int) = 1
rice.telemetry_reserved_workers (int) = 1
rice.license_reserved_workers (int) = 1
rice.log_reserved_workers (int) = 1
rice.download_reserved_workers (int) = 1
rice.misc_task_workers (int) = 3
rice.accepted_terms (bool) = false
(empty dir rice.network_pools)
rice.telemetry_enabled (bool) = true
rice.telemetry_persist (bool) = false
rice.telemetry_threads (uint) = 8
rice.enable_download (bool) = true
rice.init_performed (bool) = false
rice.ese_disconnect_alert_timeout (int) = 14400
rice.offline_collection_period (uint) = 7200

The -q flag can also be used in conjunction with the isi_gconfig command to identify any values that are not at their default settings. For example, the stock (default) Rice gconfig context will not report any configuration entries:

# isi_gconfig -q -t rice
[root] {version:1}

1. Upgrading the cluster to OneFS 9.5.
2. Obtaining the secure access key and PIN.
3. Selecting either direct connectivity or gateway connectivity.
4. If using gateway connectivity, installing Secure Connect Gateway v5.x.

In this article, we turn our attention to step 5: Provisioning SupportAssist on the cluster.

As part of this process, we’ll be using the access key and PIN credentials previously obtained from the Dell Support portal in step 2 above.

Provisioning SupportAssist on a cluster

SupportAssist can be configured from the OneFS 9.5 WebUI by going to Cluster management > General settings > SupportAssist. To initiate the provisioning process on a cluster, click the Connect SupportAssist link, as shown here:

If SupportAssist is not configured, the Remote support page displays the following banner, warning of the future deprecation of SRS:

Similarly, when SupportAssist is not configured, the SupportAssist WebUI page also displays verbiage recommending the adoption of SupportAssist:

There is also a Connect SupportAssist button to begin the provisioning process.

Selecting the Configure SupportAssist button initiates the setup wizard.

1.  Telemetry Notice

The first step requires checking and accepting the Infrastructure Telemetry Notice:

2.  Support Contract

For the next step, enter the details for the primary support contact, as prompted:

 
You can also provide the information from the CLI by using the isi supportassist contacts command set. For example:

# isi supportassist contacts modify --primary-first-name=Nick --primary-last-name=Trimbee --primary-email=trimbn@isilon.com

3.  Establish Connections

Next, complete the Establish Connections page

This involves the following steps:

• Selecting the network pool(s)
• Adding the secure access key and PIN
• Configuring either direct or gateway access
• Selecting whether to allow remote support, CloudIQ telemetry, and auto case creation
  
  

a.  Select network pool(s).

At least one statically allocated IPv4 network subnet and pool are required for provisioning SupportAssist. OneFS 9.5 does not support IPv6 networking for SupportAssist remote connectivity. However, IPv6 support is planned for a future release.

Select one or more network pools or subnets from the options displayed. In this example, we select subnet0pool0:

Or from the CLI:

Select one or more static subnets or pools for outbound communication, using the following CLI syntax:

# isi supportassist settings modify --network-pools="subnet0.pool0"

Additionally, if the cluster has the OneFS 9.5 network firewall enabled (“isi network firewall settings”), ensure that outbound traffic is allowed on port 9443.

b.  Add secure access key and PIN.

In this next step, add the secure access key and pin. These should have been obtained in an earlier step in the provisioning procedure from the following Dell Support site: https://www.dell.com/support/connectivity/product/isilon-onefs.

Alternatively, if configuring SupportAssist from the OneFS CLI, add the key and pin by using the following syntax:

# isi supportassist provision start --access-key <key> --pin <pin>

c.  Configure access.

• Direct access

Or, to configure direct access (the default) from the CLI, ensure that the following parameter is set:

# isi supportassist settings modify --connection-mode direct
# isi supportassist settings view | grep -i "connection mode"
        Connection mode: direct

• Gateway access

Alternatively, to connect through a gateway, select the Connect via Secure Connect Gateway button:

Complete the Gateway host and Gateway port fields as appropriate for the environment.

Alternatively, to set up a gateway configuration from the CLI, use the isi supportassist settings modify syntax. For example, to use the gateway FQDN secure-connect-gateway.yourdomain.com and the default port 9443:

# isi supportassist settings modify --connection-mode gateway
# isi supportassist settings view | grep -i "connection mode"
        Connection mode: gateway
# isi supportassist settings modify --gateway-host secure-connect-gateway.yourdomain.com --gateway-port 9443

When setting up the gateway connectivity option, Secure Connect Gateway v5.0 or later must be deployed within the data center. SupportAssist is incompatible with either ESRS gateway v3.52 or SAE gateway v4. However, Secure Connect Gateway v5.x is backward compatible with PowerScale OneFS ESRS, which allows the gateway to be provisioned and configured ahead of a cluster upgrade to OneFS 9.5.

d. Configure support options.

Finally, configure the support options:

When you have completed the configuration, the WebUI will confirm that SmartConnect is successfully configured and enabled, as follows:

 
Or from the CLI:

# isi supportassist settings view
        Service enabled: Yes
       Connection State: enabled
      OneFS Software ID: ELMISL0223BJJC
          Network Pools: subnet0.pool0, subnet0.testpool1, subnet0.testpool2, subnet0.testpool3, subnet0.testpool4
        Connection mode: gateway
           Gateway host: eng-sea-scgv5stg3.west.isilon.com
           Gateway port: 9443
    Backup Gateway host: eng-sea-scgv5stg.west.isilon.com
    Backup Gateway port: 9443
  Enable Remote Support: Yes
Automatic Case Creation: Yes
       Download enabled: Yes

In OneFS 9.5, several OneFS components now leverage SupportAssist as their secure off-cluster data retrieval and communication channel. These components include:

For existing clusters, SupportAssist supports the same basic workflows as its predecessor, ESRS, so the transition from old to new is generally pretty seamless.

The overall process for enabling OneFS SupportAssist is as follows:

1. Upgrade the cluster to OneFS 9.5.
2. Obtain the secure access key and PIN.
3. Select either direct connectivity or gateway connectivity.
4. If using gateway connectivity, install Secure Connect Gateway v5.x.
5. Provision SupportAssist on the cluster.

 We’ll go through each of these configuration steps in order:

1.  Upgrading to OneFS 9.5

First, the cluster must be running OneFS 9.5 to configure SupportAssist.

There are some additional considerations and caveats to bear in mind when upgrading to OneFS 9.5 and planning on enabling SupportAssist. These include:

• SupportAssist is disabled when STIG hardening is applied to the cluster.
• Using SupportAssist on a hardened cluster is not supported.
• Clusters with the OneFS network firewall enabled (”isi network firewall settings”) might need to allow outbound traffic on ports 443 and 8443, plus 9443 if gateway (SCG) connectivity is configured.
• SupportAssist is supported on a cluster that’s running in Compliance mode.
• If you are upgrading from an earlier release, the OneFS 9.5 upgrade must be committed before SupportAssist can be provisioned.

Also, ensure that the user account that will be used to enable SupportAssist belongs to a role with the ISI_PRIV_REMOTE_SUPPORT read and write privilege:

# isi auth privileges | grep REMOTE
ISI_PRIV_REMOTE_SUPPORT                           
  Configure remote support

 For example, for an ese user account:

# isi auth roles view SupportAssistRole
       Name: SupportAssistRole
Description: -
    Members: ese
 Privileges
             ID: ISI_PRIV_LOGIN_PAPI
     Permission: r
             ID: ISI_PRIV_REMOTE_SUPPORT
      Permission: w

2.  Obtaining secure access key and PIN

An access key and pin are required to provision SupportAssist, and these secure keys are held in key manager under the RICE domain. This access key and pin can be obtained from the following Dell Support site: https://www.dell.com/support/connectivity/product/isilon-onefs.

In the Quick link navigation bar, select the Generate Access key link:

 On the following page, select the appropriate button:

The credentials required to obtain an access key and pin vary, depending on prior cluster configuration. Sites that have previously provisioned ESRS will need their OneFS Software ID (SWID) to obtain their access key and pin.

The isi license list CLI command can be used to determine a cluster’s SWID. For example:

# isi license list | grep "OneFS Software ID"
OneFS Software ID: ELMISL999CKKD

However, customers with new clusters and/or customers who have not previously provisioned ESRS or SupportAssist will require their Site ID to obtain the access key and pin.

Note that any new cluster hardware shipping after January 2023 will already have an integrated key, so this key can be used in place of the Site ID.

For example, if this is the first time registering this cluster and it does not have an integrated key, select Yes, let’s register:

 Enter the Site ID, site name, and location information for the cluster:

Choose a 4-digit PIN and save it for future reference. After that, click Create My Access Key:

The access key is then generated.
 

An automated email containing the pertinent key info is sent from the Dell | ServicesConnectivity Team. For example:

This access key is valid for one week, after which it automatically expires.

Next, in the cluster’s WebUI, go back to Cluster management > General settings > SupportAssist and enter the access key and PIN information in the appropriate fields. Finally, click Finish Setup to complete the SupportAssist provisioning process:

3.  Deciding between direct or gateway topology 

A topology decision will need to be made between implementing either direct connectivity or gateway connectivity, depending on the needs of the environment:

• Direct connect:

• Gateway connect:

SupportAssist uses ports 443 and 8443 by default for bi-directional communication between the cluster and Connectivity Hub. These ports will need to be open across any firewalls or packet filters between the cluster and the corporate network edge to allow connectivity to Dell Support.

Additionally, port 9443 is used for communicating with a gateway (SCG).

# grep -i esrs /etc/services
isi_esrs_d      9443/tcp   #EMC Secure Remote Support outbound alerts

4.  Installing Secure Connect Gateway (optional) 

This step is only required when deploying Dell Secure Connect Gateway (SCG). If a direct connect topology is preferred, go directly to step 5.

When configuring SupportAssist with the gateway connectivity option, Secure Connect Gateway v5.0 or later must be deployed within the data center.

Dell SCG is available for Linux, Windows, Hyper-V, and VMware environments, and, as of this writing, the latest version is 5.14.00.16. The installation binaries can be downloaded from https://www.dell.com/support/home/en-us/product-support/product/secure-connect-gateway/drivers.

Download SCG as follows:

1. Sign in to www.dell.com/SCG-App. The Secure Connect Gateway - Application Edition page is displayed. If you have issues signing in using your business account or if you are unable to access the page even after signing in, contact Dell Administrative Support.
2. In the Quick links section, click Generate Access key.
3. On the Generate Access Keypage, perform the following steps:
   1. Select a site ID, site name, or site location.
   2. Enter a four-digit PIN and click Generate key. An access key is generated and sent to your email address. NOTE: The access key and PIN must be used within seven days and cannot be used to register multiple instances of SCG.
   3. Click Done.
4. On the Secure Connect Gateway – Application Edition page, click the Drivers & Downloads tab.
5. Search and select the required version.
6. In the ACTION column, click Download.

The following steps are required to set up SCG:

https://dl.dell.com/content/docu105633_secure-connect-gateway-application-edition-quick-setup-guide.pdf?language=en-us

 Pertinent resources for installing SCG include:

• Users guide, for system and network requirements, steps to create business account, and installation instructions: https://www.dell.com/SCG-App-docs
• Support matrix, for supported devices, protocols, firmware versions, and operating systems: https://www.dell.com/SCG-App-docs

Another useful source of SCG installation, configuration, and troubleshooting information is the Dell Support forum: https://www.dell.com/community/Secure-Connect-Gateway/bd-p/SCG

5.  Provisioning SupportAssist on the cluster

 At this point, the off-cluster prestaging work should be complete.

In the next article in this series, we turn our attention to the SupportAssist provisioning process on the cluster itself (step 5).

For enterprises to harness the advantages of advanced storage technologies with Dell PowerScale, a transition from an existing platform is necessary. Enterprises are challenged by how the new architecture will fit into the existing infrastructure. This blog post provides an overview of PowerScale architecture, features, and nomenclature for enterprises migrating from NetApp ONTAP.

PowerScale overview

The PowerScale OneFS operating system is based on a distributed architecture, built from the ground up as a clustered system. Each PowerScale node provides compute, memory, networking, and storage. The concepts of controllers, HA, active/standby, and disk shelves are not applicable in a pure scale-out architecture. Thus, when a node is added to a cluster, the cluster performance and capacity increase collectively.

Due to the scale-out distributed architecture with a single namespace, single volume, single file system, and one single pane of management, the system management is far simpler than with traditional NAS platforms. In addition, the data protection is software-based rather than RAID-based, eliminating all the associated complexities, including configuration, maintenance, and additional storage utilization. Administrators do not have to be concerned with RAID groups or load distribution.

NetApp’s ONTAP storage operating system has evolved into a clustered system with controllers. The system includes ONTAP FlexGroups composed of aggregates and FlexVols across nodes.

OneFS is a single volume, which makes cluster management simple. As the cluster grows in capacity, the single volume automatically grows. Administrators are no longer required to migrate data between volumes manually. OneFS repopulates and balances data between all nodes when a new node is added, making the node part of the global namespace. All the nodes in a PowerScale cluster are equal in the hierarchy. Drives share data intranode and internode.

PowerScale is easy to deploy, operate, and manage. Most enterprises require only one full-time employee to manage a PowerScale cluster.

For more information about the PowerScale OneFS architecture, see PowerScale OneFS Technical Overview and Dell PowerScale OneFS Operating System.

Figure 1. Dell PowerScale scale-out NAS architecture

OneFS and NetApp software features

The single volume and single namespace of PowerScale OneFS also lead to a unique feature set. Because the entire NAS is a single file system, the concepts of FlexVols, shares, qtrees, and FlexGroups do not apply. Each NetApp volume has specific properties associated with limited storage space. Adding more storage space to NetApp ONTAP could be an onerous process depending on the current architecture. Conversely, on a PowerScale cluster, as soon as a node is added, the cluster is rebalanced automatically, leading to minimal administrator management. 

NetApp’s continued dependence on volumes creates potential added complexity for storage administrators. From a software perspective, the intricacies that arise from the concept of volumes span across all the features. Configuring software features requires administrators to base decisions on the volume concept, limiting configuration options. The volume concept is further magnified by the impacts on storage utilization. 

The fact that OneFS is a single volume means that many features are not volume dependent but, rather, span the entire cluster. SnapshotIQ, NDMP backups, and SmartQuotas do not have limits based on volumes; instead, they are cluster-specific or directory-specific.

As a single-volume NAS designed for file storage, OneFS has the scalable capacity with ease of management combined with features that administrators require. Robust policy-driven features such as SmartConnect, SmartPools, and CloudPools enable maximum utilization of nodes for superior performance and storage efficiency for maximum value. You can use SmartConnect to configure access zones that are mapped to specific node performances. SmartPools can tier cold data to nodes with deep archive storage, and CloudPools can store frozen data in the cloud. Regardless of where the data is residing, it is presented as a single namespace to the end user.

Storage utilization and data protection

Storage utilization is the amount of storage available after the NAS system overhead is deducted. The overhead consists of the space required for data protection and the operating system.

For data protection, OneFS uses software-based Reed-Solomon Error Correction with up to N+4 protection. OneFS offers several custom protection options that cover node and drive failures. The custom protection options vary according to the cluster configuration. OneFS provides data protection against more simultaneous hardware failures and is software-based, providing a significantly higher storage utilization. 

The software-based data protection stripes data across nodes in stripe units, and some of the stripe units are Forward Error Correction (FEC) or parity units. The FEC units provide a variable to reformulate the data in the case of a drive or node failure. Data protection is customizable to be for node loss or hybrid protection of node and drive failure.

With software-based data protection, the protection scheme is not per cluster. It has additional granularity that allows for making data protection specific to a file or directory—without creating additional storage volumes or manually migrating data. Instead, OneFS runs a job in the background, moving data as configured.

Figure 2. OneFS data protection

OneFS protects data stored on failing nodes, or drives in a cluster through a process called SmartFail. During the process, OneFS places a device into quarantine and, depending on the severity of the issue, places the data on the device into a read-only state. While a device is quarantined, OneFS reprotects the data on the device by distributing the data to other devices. 

NetApp’s data protection is all RAID-based, including NetApp RAID-TEC, NetApp RAID-DP, and RAID 4. NetApp only supports a maximum of triple parity, and simultaneous node failures in an HA pair are not supported. 

For more information about SmartFail, see the following blog: OneFS Smartfail. For more information about OneFS data protection, see High Availability and Data Protection with Dell PowerScale Scale-Out NAS.

NetApp FlexVols, shares, and Qtrees

NetApp requires administrators to manually create space and explicitly define aggregates and flexible volumes. The concept of FlexVols, shares, and Qtrees are nonexistent in OneFS, as the file system is a single volume and namespace, spanning the entire cluster. 

SMB shares and NFS exports are created through the web or command-line interface in OneFS. Both methods allow the user to create either within seconds with security options. SmartQuotas is used to manage storage limits, cluster-wide, across the entire namespace. They include accounting, warning messages, or hard limits of enforcement. The limits can be applied by directory, user, or group. 

Conversely, ONTAP quota management is at the volume or FlexGroup level, creating additional administrative overhead because the process is more onerous.

Snapshots

The OneFS snapshot feature is SnapshotIQ, which does not have specified or enforced limits for snapshots per directory or snapshots per cluster. However, the best practice is 1,024 snapshots per directory and 20,000 snapshots per cluster. OneFS also supports writable snapshots. For more information about SnapshotIQ and writable snapshots, see High Availability and Data Protection with Dell PowerScale Scale-Out NAS.

NetApp Snapshot supports 255 snapshots per volume in ONTAP 9.3 and earlier. ONTAP 9.4 and later versions support 1,023 snapshots per volume. By default, NetApp requires a space reservation of 5 percent in the volume when snapshots are used, requiring the space reservation to be monitored and manually increased if space becomes exhausted. Further, the space reservation can also affect volume availability. The space reservation requirement creates additional administration overhead and affects storage efficiency by setting aside space that might or might not be used.

Data replication

Data replication is required for disaster recovery, RPO, or RTO requirements. OneFS provides data replication through SyncIQ and SmartSync. 

SyncIQ provides asynchronous data replication, whereas NetApp’s asynchronous replication, which is called SnapMirror, is block-based replication. SyncIQ provides options for ensuring that all data is retained during failover and failback from the disaster recovery cluster. SyncIQ is fully configurable with options for execution times and bandwidth management. A SyncIQ target cluster may be configured as a target for several source clusters. 

SyncIQ offers a single-button automated process for failover and failback with Superna Eyeglass DR Edition. For more information about Superna Eyeglass DR Edition, see Superna | DR Edition (supernaeyeglass.com).

SyncIQ allows configurable options for replication down to a specific file, directory, or entire cluster. Conversely, NetApp’s SnapMirror replication starts at the volume at a minimum. The volume concept and dependence on volume requirements continue to add management complexity and overhead for administrators while also wasting storage utilization.

To address the requirements of the modern enterprise, OneFS version 9.4.0.0 introduced SmartSync. This feature replicates file-to-file data between PowerScale clusters. SmartSync cloud copy replicates file-to-object data from PowerScale clusters to Dell ECS and cloud providers. Having multiple target destinations allows administrators to store multiple copies of a dataset across locations, providing further disaster recovery readiness. SmartSync cloud copy replicates file-to-object data from PowerScale clusters to Dell ECS and cloud providers. SmartSync cloud copy also pulls the replicated object data from a cloud provider back to a PowerScale cluster in file. For more information about SyncIQ, see Dell PowerScale SyncIQ: Architecture, Configuration, and Considerations. For more information about SmartSync, see Dell PowerScale SmartSync.

Quotas

OneFS SmartQuotas provides configurable options to monitor and enforce storage limits at the user, group, cluster, directory, or subdirectory level. ONTAP quotas are user-, tree-, volume-, or group-based.

For more information about SmartQuotas, see Storage Quota Management and Provisioning with Dell PowerScale SmartQuotas.

Load balancing and multitenancy

Because OneFS is a distributed architecture across a collection of nodes, client connectivity to these nodes requires load balancing. OneFS SmartConnect provides options for balancing the client connections to the nodes within a cluster. Balancing options are round-robin or based on current load. Also, SmartConnect zones can be configured to have clients connect based on group and performance needs. For example, the Engineering group might require high-performance nodes. A zone can be configured, forcing connections to those nodes.

NetApp ONTAP supports multitenancy with Storage Virtual Machines (SVMs), formerly vServers and Logical Interfaces (LIFs). SVMs isolate storage and network resources across a cluster of controller HA pairs. SVMs require managing protocols, shares, and volumes for successful provisioning. Volumes cannot be nondisruptively moved between SVMs. ONTAP supports load balancing using LIFs, but configuration is manual and must be implemented by the storage administrator. Further, it requires continuous monitoring because it is based on the load on the controller. 

OneFS provides multitenancy through SmartConnect and access zones. Management is simple because the file system is one volume and access is provided by hostname and directory, rather than by volume. SmartConnect is policy-driven and does not require continuous monitoring. SmartConnect settings may be changed on demand as the requirements change.

SmartConnect zones allow administrators to provision DNS hostnames specific to IP pools, subnets, and network interfaces. If only a single authentication provider is required, all the SmartConnect zones map to a default access zone. However, if directory access and authentication providers vary, multiple access zones are provisioned, mapping to a directory, authentication provider, and SmartConnect zone. As a result, authenticated users of an access zone only have visibility into their respective directory. Conversely, an administrator with complete file system access can migrate data nondisruptively between directories.

For more information about SmartConnect, see PowerScale: Network Design Considerations.

Compression and deduplication

Both ONTAP and OneFS provide compression. The OneFS deduplication feature is SmartDedupe, which allows deduplication to run at a cluster-wide level, improving overall Data Reduction Rate (DRR) and storage utilization. With ONTAP, the deduplication is enabled at the aggregate level, and it cannot cross over nodes. 

For more information about OneFS data reduction, see Dell PowerScale OneFS: Data Reduction and Storage Efficiency. For more information about SmartDedupe, see Next-Generation Storage Efficiency with Dell PowerScale SmartDedupe.

Data tiering

OneFS has integrated features to tier data based on the data’s age or file type. NetApp has similar functionality with FabricPools.

OneFS SmartPools uses robust policies to enable data placement and movement across multiple types of storage. SmartPools can be configured to move data to a set of nodes automatically. For example, if a file has not been accessed in the last 90 days, in can be migrated to a node with deeper storage, allowing admins to define the value of storage based on performance. 

OneFS CloudPools migrates data to a cloud provider, with only a stub remaining on the PowerScale cluster, based on similar policies. CloudPools not only tiers data to a cloud provider but also recalls the data back to the cluster as demanded. From a user perspective, all the data is still in a single namespace, irrespective of where it resides.

Figure 3. OneFS SmartPools and CloudPools

ONTAP tiers to S3 object stores using FabricPools.

For more information about SmartPools, see Storage Tiering with Dell PowerScale SmartPools. For more information about CloudPools, see:

• Dell PowerScale: CloudPools and Amazon Web Services
• Dell PowerScale: CloudPools and Amazon Web Services
• Dell PowerScale: CloudPools and Alibaba Cloud
• Dell PowerScale: CloudPools and Google Cloud
• Dell PowerScale: CloudPools and ECS

Monitoring

Dell InsightIQ and Dell CloudIQ provide performance monitoring and reporting capabilities. InsightIQ includes advanced analytics to optimize applications, correlate cluster events, and accurately forecast future storage needs. NetApp provides performance monitoring and reporting with Cloud Insights and Active IQ, which are accessible within BlueXP.  

For more information about CloudIQ, see CloudIQ: A Detailed Review. For more information about InsightIQ, see InsightIQ on Dell Support.

Security

Similar to ONTAP, the PowerScale OneFS operating system comes with a comprehensive set of integrated security features. These features include data at rest and data in flight encryption, virus scanning tool, WORM SmartLock compliance, external key manager for data at rest encryption, STIG-hardened security profile, Common Criteria certification, and support for UEFI Secure Boot across PowerScale platforms. Further, OneFS may be configured for a Zero Trust architecture and PCI-DSS. 

Superna security 

Superna exclusively provides the following security-focused applications for PowerScale OneFS: 

• Ransomware Defender: Provides real-time event processing through user behavior analytics. The events are used to detect and stop a ransomware attack before it occurs.
• Easy Auditor: Offers a flat-rate license model and ease-of-use features that simplify auditing and securing PBs of data.
• Performance Auditor: Provides real-time file I/O view of PowerScale nodes to simplify root cause of performance impacts, assessing changes needed to optimize performance and debugging user, network, and application performance.
• Airgap: Deployed in two configurations depending on the scale of clusters and security features:
• Basic Airgap Configuration that deploys the Ransomware Defender agent on one of the primary clusters being protected.
• Enterprise Airgap Configuration that deploys the Ransomware Defender agent on the cyber vault cluster. This solution comes with greater scalability and additional security features.

Figure 4. Superna security

NetApp ONTAP security is limited to the integrated features listed above. Additional applications for further security monitoring, like Superna, are not available for ONTAP.

For more information about Superna security, see supernaeyeglass.com. For more information about PowerScale security, see Dell PowerScale OneFS: Security Considerations.

Authentication and access control

NetApp and PowerScale OneFS both support several methods for user authentication and access control. OneFS supports UNIX and Windows permissions for data-level access control. OneFS is designed for a mixed environment that allows the configuration of both Windows Access Control Lists (ACLs) and standard UNIX permissions on the cluster file system. In addition, OneFS provides user and identity mapping, permission mapping, and merging between Windows and UNIX environments.

OneFS supports local and remote authentication providers. Anonymous access is supported for protocols that allow it. Concurrent use of multiple authentication provider types, including Active Directory, LDAP, and NIS, is supported. For example, OneFS is often configured to authenticate Windows clients with Active Directory and to authenticate UNIX clients with LDAP.

Role-based access control

OneFS supports role-based access control (RBAC), allowing administrative tasks to be configured without a root or administrator account. A role is a collection of OneFS privileges that are limited to an area of administration. Custom roles for security, auditing, storage, or backup tasks may be provisioned with RBACs. Privileges are assigned to roles. As users log in to the cluster through the platform API, the OneFS command-line interface, or the OneFS web administration interface, they are granted privileges based on their role membership.

For more information about OneFS authentication and access control, see PowerScale OneFS Authentication, Identity Management, and Authorization.

Learn more about PowerScale OneFS

To learn more about PowerScale OneFS, see the following resources:

• Dell PowerScale Info Hub
• PowerScale OneFS Technical Overview
• Dell PowerScale OneFS Operating System
• OneFS Smartfail blog post
• High Availability and Data Protection with Dell PowerScale Scale-Out NAS
• Dell PowerScale SyncIQ: Architecture, Configuration, and Considerations
• Dell PowerScale: NDMP Technical Overview and Design Considerations
• Storage Quota Management and Provisioning with Dell PowerScale SmartQuotas
• PowerScale: Network Design Considerations
• Dell PowerScale OneFS: Data Reduction and Storage Efficiency
• Next-Generation Storage Efficiency with Dell PowerScale SmartDedupe
• Storage Tiering with Dell PowerScale SmartPools 
• Dell PowerScale: CloudPools and Amazon Web Services
• Dell PowerScale: CloudPools and Microsoft Azure
• Dell PowerScale: CloudPools and Alibaba Cloud
• Dell PowerScale: CloudPools and Google Cloud
• Dell PowerScale: CloudPools and ECS
• CloudIQ: A Detailed Review
• InsightIQ (Dell Support page with documentation links)
• Dell PowerScale OneFS: Security Considerations
• PowerScale OneFS Authentication, Identity Management, and Authorization
• Superna website (supernaeyeglass.com)

The previous articles in this series have covered the SmartQoS architecture, configuration, and management. Now, we’ll turn our attention to monitoring and troubleshooting.

You can use the ‘isi statistics workload’ CLI command to monitor the dataset’s performance. The ‘Ops’ column displays the current protocol operations per second. In the following example, Ops stabilize around 9.8, which is just below the configured limit value of 10 Ops.

# isi statistics workload --dataset ds1 & data

Similarly, this next example from the SmartQoS WebUI shows a small NFS workflow performing 497 protocol Ops in a pinned workload with a limit of 500 Ops:

You can pin multiple paths and protocols by selecting the ‘Pin Workload’ option for a given Dataset. Here, four directory path workloads are each configured with different Protocol Ops limits:

When it comes to troubleshooting SmartQoS, there are a few areas that are worth checking right away, including the SmartQoS Ops limit configuration, isi_pp_d and isi_stats_d daemons, and the protocol service(s).

  1. For suspected Ops limit configuration issues, first confirm that the SmartQoS limits feature is enabled:

# isi performance settings view
Top N Collections: 1024
Time In Queue Threshold (ms): 10.0
Target read latency in microseconds: 12000.0
Target write latency in microseconds: 12000.0
Protocol Ops Limit Enabled: Yes

Next, verify that the workload level protocols_ops limit is correctly configured:

# isi performance workloads view <workload>

Check whether any errors are reported in the isi_tardis_d configuration log:

# cat /var/log/isi_tardis_d.log

  2. To investigate isi_pp_d, first check that the service is enabled:

# isi services –a isi_pp_d
Service 'isi_pp_d' is enabled.

If necessary, you can restart the isi_pp_d service as follows:

# isi services isi_pp_d disable
Service 'isi_pp_d' is disabled.
# isi services isi_pp_d enable
Service 'isi_pp_d' is enabled.

There’s also an isi_pp_d debug tool, which can be helpful in a pinch:

# isi_pp_d -h
Usage: isi_pp_d [-ldhs]
-l Run as a leader process; otherwise, run as a follower. Only one leader process on the cluster will be active.
-d Run in debug mode (do not daemonize).
-s Display pp_leader node (devid and lnn)
-h Display this help.

You can enable debugging on the isi_pp_d log file with the following command syntax:

# isi_ilog -a isi_pp_d -l debug, /var/log/isi_pp_d.log

For example, the following log snippet shows a typical isi_ppd_d.log message communication between isi_pp_d leader and isi_pp_d followers:

/ifs/.ifsvar/modules/pp/comm/SETTINGS
[090500b000000b80,08020000:0000bfddffffffff,09000100:ffbcff7cbb9779de,09000100:d8d2fee9ff9e3bfe,090001 00:0000000075f0dfdf]      
100,,,,20,1658854839  < in the format of <workload_id, cputime, disk_reads, disk_writes, protocol_ops, timestamp>

Here, the extract from the /var/log/isi_pp_d.log logfiles from nodes 1 and 2 of a cluster illustrate the different stages of Protocol Ops limit enforcement and usage:

  3. To investigate the isi_stats_d, first confirm that the isi_pp_d service is enabled:

# isi services -a isi_stats_d
Service 'isi_stats_d' is enabled.

If necessary, you can restart the isi_stats_d service as follows:

# isi services isi_stats_d disable
# isi services isi_stats_d enable

You can view the workload level statistics with the following command:

# isi statistics workload list --dataset=<name>

You can enable debugging on the isi_stats_d log file with the following command syntax:

# isi_stats_tool --action set_tracelevel --value debug
# cat /var/log/isi_stats_d.log

  4. To investigate protocol issues, the ‘isi services’ and ‘lwsm’ CLI commands can be useful. For example, to check the status of the S3 protocol:

# /usr/likewise/bin/lwsm list | grep -i protocol
hdfs                       [protocol]    stopped
lwswift                    [protocol]    running (lwswift: 8393)
nfs                        [protocol]    running (nfs: 8396)
s3                         [protocol]    stopped
srv                        [protocol]    running (lwio: 8096)
# /usr/likewise/bin/lwsm status s3
stopped
# /usr/likewise/bin/lwsm info s3
Service: s3
Description: S3 Server
Categories: protocol
Path: /usr/likewise/lib/lw-svcm/s3.so
Arguments:
Dependencies: lsass onefs_s3 AuditEnabled?flt_audit_s3
Container: s3

This CLI output confirms that the S3 protocol is inactive. You can start the S3 service as follows:

# isi services -a | grep -i s3
s3                   S3
Service                               Enabled

Similarly, you can restart the S3 service as follows:

# /usr/likewise/bin/lwsm restart s3
Stopping service: s3
Starting service: s3

To investigate further, you can increase the protocol’s log level verbosity. For example, to set the s3 log to ‘debug’:

# isi s3 log-level view
Current logging level is 'info'
# isi s3 log-level modify debug
# isi s3 log-level view
Current logging level is 'debug'

Next, view and monitor the appropriate protocol log. For example, for the S3 protocol:

# cat /var/log/s3.log
# tail -f /var/log/s3.log

Beyond the above, you can monitor /var/log/messages for pertinent errors, because the main partition performance (PP) modules log to this file. You can enable debug level logging for the various PP modules as follows.

Dataset:

# sysctl ilog.ifs.acct.raa.syslog=debug+
ilog.ifs.acct.raa.syslog: error,warning,notice (inherited) -> error,warning,notice,info,debug

Workload:

# sysctl ilog.ifs.acct.rat.syslog=debug+
ilog.ifs.acct.rat.syslog: error,warning,notice (inherited) -> error,warning,notice,info,debug

Actor work:

# sysctl ilog.ifs.acct.work.syslog=debug+
ilog.ifs.acct.work.syslog: error,warning,notice (inherited) -> error,warning,notice,info,debug

When finished, you can restore the default logging levels for the above modules as follows:

# sysctl ilog.ifs.acct.raa.syslog=notice+
# sysctl ilog.ifs.acct.rat.syslog=notice+
# sysctl ilog.ifs.acct.work.syslog=notice+

Author: Nick Trimbee

In the previous article in this series, we looked at the underlying architecture and management of SmartQoS in OneFS 9.5. Next, we’ll step through an example SmartQoS configuration using the CLI and WebUI.

After an initial set up, configuring a SmartQoS protocol Ops limit comprises four fundamental steps. These are:

Step 1:

First, select a metric of interest. For this example, we’ll use the following:

• Protocol: NFSv3
• Path: /ifs/test/expt_nfs

If not already present, create and verify an NFS export – in this case at /ifs/test/expt_nfs:

# isi nfs exports create /ifs/test/expt_nfs
# isi nfs exports list
ID Zone Paths Description
------------------------------------------------
1 System /ifs/test/expt_nfs
------------------------------------------------

Or from the WebUI, under Protocols UNIX sharing (NFS) > NFS exports:

Step 2:

The ‘dataset’ designation is used to categorize workload by various identification metrics, including:

SmartQoS in OneFS 9.5 only allows protocol Ops as the transient resources used for configuring a limit ceiling.

For example, you can use the following CLI command to create a dataset ‘ds1’, specifying protocol and path as the ID metrics:

# isi performance datasets create --name ds1 protocol path
Created new performance dataset 'ds1' with ID number 1.

Note: Resource usage tracking by the ‘path’ metric is only supported by SMB and NFS.

The following command displays any configured datasets:

# isi performance datasets list

Or, from the WebUI, by navigating to Cluster management > Smart QoS:

Step 3:

After you have created the dataset, you can pin a workload to it by specifying the metric values. For example:

# isi performance workloads pin ds1 protocol:nfs3 path: /ifs/test/expt_nfs

Pinned performance dataset workload with ID number 100.

Or from the WebUI, by browsing to Cluster management > Smart QoS > Pin workload:

After pinning a workload, the entry appears in the ‘Top Workloads’ section of the WebUI page. However, wait at least 30 seconds to start receiving updates.

To list all the pinned workloads from a specified dataset, use the following command:

# isi performance workloads list ds1

The prior command’s output indicates that there are currently no limits set for this workload.

By default, a protocol ops limit exists for each workload. However, it is set to the maximum (the maximum value of a 64-bit unsigned integer). This is represented in the CLI output by a dash (“-“) if a limit has not been explicitly configured:

# isi performance workloads list ds1
ID   Name  Metric Values           Creation Time       Cluster Resource Impact  Client Impact   Limits
--------------------------------------------------------------------------------------
100  -     path:/ifs/test/expt_nfs 2023-02-02T12:06:05  -          -              -
           protocol:nfs3
--------------------------------------------------------------------------------------
Total: 1

Step 4:

For a pinned workload in a dataset, you can configure a limit for the protocol ops limit from the CLI, using the following syntax:

# isi performance workloads modify <dataset> <workload ID> --limits protocol_ops:<value>

When configuring SmartQoS, always be aware that it is a powerful performance throttling tool which can be applied to significant areas of a cluster’s data and userbase. For example, protocol Ops limits can be configured for metrics such as ‘path:/ifs’, which would affect the entire /ifs filesystem, or ‘zone_name:System’ which would limit the System access zone and all users within it. While such configurations are entirely valid, they would have a significant, system-wide impact. As such, exercise caution when configuring SmartQoS to avoid any inadvertent, unintended, or unexpected performance constraints.

In the following example, the dataset is ‘ds1’, the workload ID is ‘100’, and the protocol Ops limit is set to the value ‘10’:

# isi performance workloads modify ds1 100 --limits protocol_ops:10
protocol_ops: 18446744073709551615 -> 10

Or from the WebUI, by browsing to Cluster management > Smart QoS > Pin and throttle workload:

You can use the ‘isi performance workloads’ command in ‘list’ mode to show details of the workload ‘ds1’. In this case, ‘Limits’ is set to protocol_ops = 10.

# isi performance workloads list test
ID   Name  Metric Values           Creation Time       Cluster Resource Impact  Client Impact   Limits
--------------------------------------------------------------------------------------
100  -     path:/ifs/test/expt_nfs 2023-02-02T12:06:05  -   -  protocol_ops:10
           protocol:nfs3
--------------------------------------------------------------------------------------
Total: 1

Or in ‘view’ mode:

# isi performance workloads view ds1 100
                     ID: 100
                   Name: -
          Metric Values: path:/ifs/test/expt_nfs, protocol:nfs3
          Creation Time: 2023-02-02T12:06:05
Cluster Resource Impact: -
          Client Impact: -
                 Limits: protocol_ops:10

Or from the WebUI, by browsing to Cluster management > Smart QoS:

You can easily modify the limit value of a pinned workload with the following CLI syntax. For example, to set the limit to 100 Ops:

# isi performance workloads modify ds1 100 --limits protocol_ops:100

Or from the WebUI, by browsing to Cluster management > Smart QoS > Edit throttle:

Similarly, you can use the following CLI command to easily remove a protocol ops limit for a pinned workload:

# isi performance workloads modify ds1 100 --no-protocol-ops-limit

Or from the WebUI, by browsing to Cluster management > Smart QoS > Remove throttle:

Author: Nick Trimbee

Among the myriad of new features included in the OneFS 9.5 release is SupportAssist, Dell’s next-gen remote connectivity system. SupportAssist is included with all support plans (features vary based on service level agreement).

Dell SupportAssist rapidly identifies, diagnoses, and resolves cluster issues and provides the following key benefits:

• Improves productivity by replacing manual routines with automated support
• Accelerates resolution, or avoid issues completely, with predictive issue detection and proactive remediation

Within OneFS, SupportAssist transmits events, logs, and telemetry from PowerScale to Dell support. As such, it provides a full replacement for the legacy ESRS.

Delivering a consistent remote support experience across the Dell storage portfolio, SupportAssist is intended for all sites that can send telemetry off-cluster to Dell over the Internet. SupportAssist integrates the Dell Embedded Service Enabler (ESE) into PowerScale OneFS along with a suite of daemons to allow its use on a distributed system.

 Using the Dell Connectivity Hub, SupportAssist can either interact directly or through a Secure Connect gateway. 

SupportAssist has a variety of components that gather and transmit various pieces of OneFS data and telemetry to Dell Support and backend services through the Embedded Service Enabler (ESE). These workflows include CELOG events; In-product activation (IPA) information; CloudIQ telemetry data; Isi-Gather-info (IGI) logsets; and provisioning, configuration, and authentication data to ESE and the various backend services.

SupportAssist requires an access key and PIN, or hardware key, to be enabled, with most customers likely using the access key and pin method. Secure keys are held in key manager under the RICE domain.

In addition to the transmission of data from the cluster to Dell, Connectivity Hub also allows inbound remote support sessions to be established for remote cluster troubleshooting.

 In the next article in this series, we’ll take a deeper look at the SupportAssist architecture and operation.

The SmartQoS Protocol Ops limits architecture, introduced in OneFS 9.5, involves three primary capabilities:

• Resource tracking
• Resource limit distribution
• Throttling

Under the hood, the OneFS protocol heads (NFS, SMB, and S3) identify and track how many protocol operations are being processed through a specific export or share. The existing partitioned performance (PP) reporting infrastructure is leveraged for cluster wide resource usage collection, limit calculation and distribution, along with new OneFS 9.5 functionality to support pinned workload protocol Ops limits.

The protocol scheduling module (LwSched) has a built-in throttling capability that allows the execution of individual operations to be delayed by temporarily pausing them, or ‘sleeping’. Additionally, in OneFS 9.5, the partitioned performance kernel modules have also been enhanced to calculate ‘sleep time’ based on operation count resource information (requested, average usage, and so on) – both within the current throttling window, and for a specific workload.

We can characterize the fundamental SmartQoS workflow as follows:

1. Configuration, using the CLI, pAPI, or WebUI.
2. Statistics gatherer obtains Op/s data from the partitioned performance (PP) kernel.
3. Stats gatherer communicates Op/s data to PP leader service.
4. Leader queries config manager for per-cluster rate limit.
5. Leader calculates per-node limit.
6. PP follower service is notified of per-node Op/s limit.
7. Kernel is informed of new per-node limit.
8. Work is scheduled with rate-limited resource.
9. Kernel returns sleep time, if needed.

When an admin configures a per-cluster protocol Ops limit, the statistics gathering service, isi_stats_d, begins collecting workload resource information every 30 seconds by default from the partitioned performance (PP) kernel on each node in the cluster and notifies the isi_pp_d leader service of this resource info. Next, the leader gets the per-cluster protocol Ops limit plus additional resource consumption metrics from the isi_acct_cpp service from isi_tardis_d, the OneFS cluster configuration service and calculates the protocol Ops limit of each node for the next throttling window. It then instructs the isi_pp_d follower service on each node to update the kernel with the newly calculated protocol Ops limit, plus a request to reset the throttling window.

When the kernel receives a scheduling request for a work item from the protocol scheduler (LwSched), the kernel calculates the required ‘sleep time’ value, based on the current node protocol Ops limit and resource usage in the current throttling window. If insufficient resources are available, the work item execution thread is put to sleep for a specific interval returned from the PP kernel. If resources are available, or the thread is reactivated from sleeping, it executes the work item and reports the resource usage statistics back to PP, releasing any scheduling resources it may own.

SmartQoS can be configured through either the CLI, platform API, or WebUI, and OneFS 9.5 introduces a new SmartQoS WebUI page to support this. Note that SmartQoS is only available when an upgrade to OneFS 9.5 has been committed, and any attempt to configure or run the feature prior to upgrade commit will fail with the following message:

# isi performance workloads modify DS1 -w WS1 --limits protocol_ops:50000
 Setting of protocol ops limits not available until upgrade has been committed

When a cluster is running OneFS 9.5 and the release is committed, the SmartQoS feature is enabled by default. This, and the current configuration, can be confirmed using the following CLI command:

 # isi performance settings view
                   Top N Collections: 1024
        Time In Queue Threshold (ms): 10.0
 Target read latency in microseconds: 12000.0
Target write latency in microseconds: 12000.0
          Protocol Ops Limit Enabled: Yes

In OneFS 9.5, the ‘isi performance settings modify’ CLI command now includes a ‘protocol-ops-limit-enabled’ parameter to allow the feature to be easily disabled (or re-enabled) across the cluster. For example:

# isi performance settings modify --protocol-ops-limit-enabled false
protocol_ops_limit_enabled: True -> False

Similarly, the ‘isi performance settings view’ CLI command has been extended to report the protocol OPs limit state:

# isi performance settings view *
Top N Collections: 1024
Protocol Ops Limit Enabled: Yes

In order to set a protocol OPs limit on workload from the CLI, the ‘isi performance workload pin’ and ‘isi performance workload modify’ commands now accept an optional ‘–limits’ parameter. For example, to create a pinned workload with the ‘protocol_ops’ limit set to 10000:

# isi performance workload pin test protocol:nfs3 --limits
protocol_ops:10000

Similarly, to modify an existing workload’s ‘protocol_ops’ limit to 20000:

# isi performance workload modify test 101 --limits protocol_ops:20000
protocol_ops: 10000 -> 20000

When configuring SmartQoS, always be aware that it is a powerful throttling tool that can be applied to significant areas of a cluster’s data and userbase. For example, protocol OPs limits can be configured for metrics such as ‘path:/ifs’, which would affect the entire /ifs filesystem, or ‘zone_name:System’ which would limit the System access zone and all users within it.

While such configurations are entirely valid, they would have a significant, system-wide impact. As such, exercise caution when configuring SmartQoS to avoid any inadvertent, unintended, or unexpected performance constraints.

To clear a protocol Ops limit on workload, the ‘isi performance workload modify’ CLI command has been extended to accept an optional ‘–noprotocol-ops-limit’ argument. For example:

# isi performance workload modify test 101 --no-protocol-ops-limit
protocol_ops: 20000 -> 18446744073709551615

Note that the value of ‘18446744073709551615’ in the command output above represents ‘NO_LIMIT’ set.

You can view a workload’s protocol Ops limit by using the ‘isi performance workload list’ and ‘isi performance workload view’ CLI commands, which have been modified in OneFS 9.5 to display the limits appropriately. For example:

# isi performance workload list test
ID Name Metric Values Creation Time Impact Limits
---------------------------------------------------------------------
101 - protocol:nfs3 2023-02-02T22:35:02 - protocol_ops:20000
---------------------------------------------------------------------
# isi performance workload view test 101
ID: 101
Name: -
Metric Values: protocol:nfs3
Creation Time: 2023-02-02T22:35:02
Impact: -
Limits: protocol_ops:20000

In the next article in this series, we’ll step through an example SmartQoS configuration and verification from both the CLI and WebUI.

Author: Nick Trimbee

Built atop the partitioned performance (PP) resource monitoring framework, OneFS 9.5 introduces a new SmartQoS performance management feature. SmartQoS allows a cluster administrator to set limits on the maximum number of protocol operations per second (Protocol Ops) that individual pinned workloads can consume, in order to achieve desired business workload prioritization. Among the benefits of this new QoS functionality are:

• Enabling IT infrastructure teams to achieve performance SLAs
• Allowing throttling of rogue or low priority workloads and hence prioritization of other business critical workloads
• Helping minimize data unavailability events due to overloaded clusters

This new SmartQoS feature in OneFS 9.5 supports the NFS, SMB and S3 protocols, including mixed traffic to the same workload.

But first, a quick refresher. The partitioned performance resource monitoring framework, which initially debuted in OneFS 8.0.1, enables OneFS to track and report the use of transient system resources (resources that only exist at a given instant), providing insight into who is consuming what resources, and how much of them. Examples include CPU time, network bandwidth, IOPS, disk accesses, and cache hits, and so on.

OneFS partitioned performance is an ongoing project that in OneFS 9.5 now provides control and insights. This allows control of work flowing through the system, prioritization and protection of mission critical workflows, and the ability to detect if a cluster is at capacity.

Because identification of work is highly subjective, OneFS partitioned performance resource monitoring provides significant configuration flexibility, by allowing cluster admins to craft exactly how they want to define, track, and manage workloads. For example, an administrator might want to partition their work based on criteria such as which user is accessing the cluster, the export/share they are using, which IP address they’re coming from – and often a combination of all three.

OneFS has always provided client and protocol statistics, but they were typically front-end only. Similarly, OneFS has provided CPU, cache, and disk statistics, but they did not display who was consuming them. Partitioned performance unites these two realms, tracking the usage of the CPU, drives, and caches, and spanning the initiator/participant barrier.

OneFS collects the resources consumed and groups them into distinct workloads. The aggregation of these workloads comprises a performance dataset.

The following metrics are tracked by partitioned performance resource monitoring:

Be aware that, in OneFS 9.5, SmartQoS currently does not support the following Partitioned Performance criteria:

When pinning a workload to a dataset, note that the more metrics there are in that dataset, the more parameters need to be defined when pinning to it. For example:

Dataset = zone_name, protocol, username

To set a limit on this dataset, you’d need to pin the workload by also specifying the zone name, protocol, and username.

When using the remote_address and/or local_address metrics, you can also specify a subnet. For example: 10.123.456.0/24

With the exception of the system dataset, you must configure performance datasets before statistics are collected.

For SmartQoS in OneFS 9.5, you can define and configure limits as a maximum number of protocol operations (Protocol Ops) per second across the following protocols:

• NFSv3
• NFSv4
• NFSoRDMA
• SMB
• S3

You can apply a Protocol Ops limit to up to four custom datasets. All pinned workloads within a dataset can have a limit configured, up to a maximum of 1024 workloads per dataset. If multiple workloads happen to share a common metric value with overlapping limits, the lowest limit that is configured would be enforced

Note that when upgrading to OneFS 9.5, SmartQoS is activated only when the new release has been successfully committed.

In the next article in this series, we’ll take a deeper look at SmartQoS’ underlying architecture and workflow.

Author: Nick Trimbee

In the first article in this series, we looked at the architecture and considerations of the new SmartPools transfer limits in OneFS 9.5. Now, we turn our attention to the configuration and management of this feature.

From the control plane side, OneFS 9.5 contains several WebUI and CLI enhancements to reflect the new SmartPools transfer limits functionality. Probably the most obvious change is in the Local storage usage status histogram, where tiers and their child node pools have been aggregated for a more logical grouping. Also, blue limit-lines have been added above each of the storage pools, and a red warning status is displayed for any pools that have exceeded the transfer limit.

Similarly, the storage pools status page now includes transfer limit details, with the 90% limit displayed for any storage pools using the default setting.

From the CLI, the isi storagepool nodepools view command reports the transfer limit status and percentage for a pool. The used SSD and HDD bytes percentages in the command output indicate where the pool utilization is relative to the transfer limit.

The storage transfer limit can be easily configured from the CLI as either for a  specific pool, as a default, or disabled, using the new –transfer-limit and –default-transfer-limit flags.

The following CLI command can be used to set the transfer limit for a specific storage pool:

# isi storagepool nodepools/tier modify --transfer-limit={0-100, default, disabled} 

For example, to set a limit of 80% on an A200 nodepool:

# isi storagepool a200_30tb_1.6tb-ssd_96gb modify --transfer-limit=80 

Or to set the default limit of 90% on tier perf1:

# isi storagepool perf1 --transfer-limit=default 

Note that setting the transfer limit of a tier automatically applies to all its child node pools, regardless of any prior child limit configurations.

The global isi storage settings view CLI command output shows the default transfer limit, which is 90%, but it can be configured between 0 to 100%.

This default limit can be reconfigured from the CLI with the following syntax:

# isi storagepool settings modify --default-transfer-limit={0-100, disabled}

For example, to set a new default transfer limit of 85%:

# isi storagepool settings modify --default-transfer-limit=85

And the same changes can be made from the SmartPools WebUI, by navigating to Storage pools > SmartPools settings:

 Once a SmartPools job has been completed in OneFS 9.5, the job report contains a new field, files not moved due to transfer limit exceeded.

# isi job reports view 1056 
... 
... 
Policy/testpolicy/Access changes skipped 0 
Policy/testpolicy/ADS containers matched 'head’ 0 
Policy/testpolicy/ADS containers matched 'snapshot’ 0 
Policy/testpolicy/ADS streams matched 'head’ 0 
Policy/testpolicy/ADS streams matched 'snapshot’ 0 
Policy/testpolicy/Directories matched 'head’ 0 
Policy/testpolicy/Directories matched 'snapshot’ 0 
Policy/testpolicy/File creation templates matched 0 
Policy/testpolicy/Files matched 'head’ 0 
Policy/testpolicy/Files matched 'snapshot’ 0 
Policy/testpolicy/Files not moved due to transfer limit exceeded 0 
Policy/testpolicy/Files packed 0 
Policy/testpolicy/Files repacked 0 
Policy/testpolicy/Files unpacked 0 
Policy/testpolicy/Packing changes skipped 0 
Policy/testpolicy/Protection changes skipped 0 
Policy/testpolicy/Skipped files already in containers 0 
Policy/testpolicy/Skipped packing non-regular files 0 
Policy/testpolicy/Skipped packing regular files 0

Additionally, the SYS STORAGEPOOL FILL LIMIT EXCEEDED alert is triggered at the Info level when a storage pool’s usage has exceeded its transfer limit. Each hour, CELOG fires off a monitor helper script that measures how full each storage pool is relative to its transfer limit. The usage is gathered by reading from the disk pool database, and the transfer limits are stored in gconfig. If a node pool has a transfer limit of 50% and usage of 75%, the monitor helper would report a measurement of 150%, triggering an alert.

# isi event view 126 
ID: 126 
Started: 11/29 20:32 
Causes Long: storagepool: vonefs_13gb_4.2gb-ssd_6gb:hdd usage: 33.4, transfer limit: 30.0 
Lnn: 0 
Devid: 0 
Last Event: 2022-11-29T20:32:16 
Ignore: No 
Ignore Time: Never 
Resolved: No 
Resolve Time: Never 
Ended: -- 
Events: 1 
Severity: information

And from the WebUI:

And there you have it: Transfer limits, and the first step in the evolution toward a smarter SmartPools.

The new OneFS 9.5 release introduces the first phase of engineering’s Smarter SmartPools initiative, and delivers a new feature called SmartPools transfer limits.

The goal of SmartPools Transfer Limits is to address spill over. Previously, when file pool policies were executed, OneFS had no guardrails to protect against overfilling the destination or target storage pool. So if a pool was overfilled, data would unexpectedly spill over into other storage pools.

An overflow would result in storagepool usage exceeding 100%, and cause the SmartPools job itself to do a considerable amount of unnecessary work, trying to send files to a given storagepool. But because the pool was full, it would then have to send those files off to another storage pool that was below capacity. This would result in data going where it wasn’t intended, and the potential for individual files to end up getting split between pools. Also, if the full pool was on the most highly performing storage in the cluster, all subsequent newly created data would now land on slower storage, affecting its throughput and latency. The recovery from a spillover can be fairly cumbersome because it’s tough for the cluster to regain balance, and urgent system administration may be required to free space on the affected tier.

In order to address this, SmartPools Transfer Limits allows a cluster admin to configure a storagepool capacity-usage threshold, expressed as a percentage, and beyond which file pool policies stop moving data to that particular storage pool.

These transfer limits only take effect when running jobs that apply filepool policies, such as SmartPools, SmartPoolsTree, and FilePolicy.

The main benefits of this feature are two-fold:

• Safety, in that OneFS avoids undesirable actions, so the customer is prevented from getting into escalation situations, because SmartPools won’t overfill storage pools.
• Performance, because transfer limits avoid unnecessary work, and allow the SmartPools job to finish sooner.

Under the hood, a cluster’s storagepool SSD and HDD usage is calculated using the same algorithm as reported by the ‘isi storagepools list’ CLI command. This means that a pool’s VHS (virtual hot spare) reserved capacity is respected by SmartPools transfer limits. When a SmartPools job is running, there is at least one worker on each node processing a single LIN at any given time. In order to calculate the current HDD and SSD usage per storagepool, the worker must read from the diskpool database. To circumvent this potential bottleneck, the filepool policy algorithm caches the diskpool database contents in memory for up to 10 seconds.

Transfer limits are stored in gconfig, and a separate entry is stored within the ‘smartpools.storagepools’ hierarchy for each explicitly defined transfer limit.

Note that in the SmartPools lexicon, ‘storage pool’ is a generic term denoting either a tier or nodepool. Additionally, SmartPools tiers comprise one or more constituent nodepools.

Each gconfig transfer limit entry stores a limit value and the diskpool database identifier of the storagepool to which the transfer limit applies. Additionally, a ‘transfer limit state’ field specifies which of three states the limit is in:

A SmartPools transfer limit does not affect the general ingress, restriping, or reprotection of files, regardless of how full the storage pool is where that file is located. So if you’re creating or modifying a file on the cluster, it will be created there anyway. This will continue up until the pool reaches 100% capacity, at which point it will then spill over.

The default transfer limit is 90% of a pool’s capacity. This applies to all storage pools where the cluster admin hasn’t explicitly set a threshold. Note also that the default limit doesn’t get set until a cluster upgrade to OneFS 9.5 has been committed. So if you’re running a SmartPools policy job during an upgrade, you’ll have the preexisting behavior, which is to send the file to wherever the file pool policy instructs it to go. It’s also worth noting that, even though the default transfer limit is set on commit, if a job was running over that commit edge, you’d have to pause and resume it for the new limit behavior to take effect. This is because the new configuration is loaded lazily when the job workers are started up, so even though the configuration changes, a pause and resume is needed to pick up those changes.

SmartPools itself needs to be licensed on a cluster in order for transfer limits to work. And limits can be configured at the tier or nodepool level. But if you change the limit of a tier, it automatically applies to all of its child nodepools, regardless of any prior child limit configurations. The transfer limit feature can also be disabled, which results in the same spillover behavior OneFS always displayed, and any configured limits will not be respected.

Note that a filepool policy’s transfer limits algorithm does not consider the size of the file when deciding whether to move it to the policy’s target storagepool, regardless of whether the file is empty, or a large file. Similarly, a target storagepool’s usage must exceed its transfer limit before the filepool policy will stop moving data to that target pool. The assumption here is that any storagepool usage overshoot is insignificant in scale compared to the capacity of a cluster’s storagepool.

A SmartPools file pool policy allows you to send snapshot or HEAD data blocks to different targets, if so desired.

Because the transfer limit applies to the storagepool itself, and not to the file pool policy, it’s important to note that, if you’ve got varying storagepool targets and one file pool policy, you may have a situation where the head data blocks do get moved. But if the snapshot is pointing at a storage pool that has exceeded its transfer limit, its blocks will not be moved.

File pool policies also allow you to specify how a mixed node’s SSDs are used: either as L3 cache, or as an SSD strategy for head and snapshot blocks. If the SSDs in a node are configured for L3, they are not being used for storage, so any transfer limits are irrelevant to it. As an alternative to L3 cache, SmartPools offers three main categories of SSD strategy:  

• Avoid, which means send all blocks to HDD 
• Data, which means send everything to SSD 
• Metadata Read or Write, which sends varying numbers of metadata mirrors to SSD, and data blocks to hard disk.

To reflect this, SmartPools transfer limits are slightly nuanced when it comes to SSD strategies. That is, if the storagepool target contains both HDD and SSD, the usage capacity of both mediums needs to be below the transfer limit in order for the file to be moved to that target. For example, take two node pools, NP1 and NP2.

A file pool policy, Pol1, is configured and which matches all files under /ifs/dir1, with an SSD strategy of Metadata Write, and pool NP1 as the target for HEAD’s data blocks. For snapshots, the target is NP2, with an ‘avoid’ SSD strategy, so just writing to hard disk for both snapshot data and metadata.

When a SmartPools job runs and attempts to apply this file pool policy, it sees that SSD usage is above the 85% configured transfer limit for NP1. So, even though the hard disk capacity usage is below the limit, neither HEAD data nor metadata will be sent to NP1.

For the snapshot, the SSD usage is also above the NP2 pool’s transfer limit of 90%.

However, because the SSD strategy is ‘avoid’, and because the hard disk usage is below the limit, the snapshot’s data and metadata get successfully sent to the NP2 HDDs.

Author: Nick Trimbee

PowerScale – the world’s most flexible[1] and cyber-secure scale-out NAS solution[2]  – is powering up the new year with the launch of the innovative OneFS 9.5 release. With data integrity and protection being top of mind in this era of unprecedented corporate cyber threats, OneFS 9.5 brings an array of new security features and functionality to keep your unstructured data and workloads more secure than ever, as well as delivering significant performance gains on the PowerScale nodes – such as up to 55% higher performance on all-flash F600 and F900 nodes as compared with the previous OneFS release.[3]   

OneFS and hardware security features 

New PowerScale OneFS 9.5 security enhancements include those that directly satisfy US Federal and DoD mandates, such as FIPS 140-2, Common Criteria, and DISA STIGs – in addition to general enterprise data security requirements. Multi-factor authentication (MFA), single sign-on (SSO) support, data encryption in-flight and at rest, TLS 1.2, USGv6R1 IPv6 support, SED Master Key rekey, plus a new host-based firewall are all part of OneFS 9.5. 

15TB and 30TB self-encrypting (SED) SSDs now enable PowerScale platforms running OneFS 9.5 to scale up to 186 PB of encrypted raw capacity per cluster – all within a single volume and filesystem, and before any additional compression and deduplication benefit.  

Delivering federal-grade security to protect data under a zero trust model 

Security-wise, the United States Government has stringent requirements for infrastructure providers such as Dell Technologies, requiring vendors to certify that products comply with requirements such as USGv6, STIGs, DoDIN APL, Common Criteria, and so on. Activating the OneFS 9.5 cluster hardening option implements a default maximum security configuration with AES and SHA cryptography, which automatically renders a cluster FIPS 140-2 compliant. 

OneFS 9.5 introduces SAML-based single sign-on (SSO) from both the command line and WebUI using a redesigned login screen. OneFS SSO is compatible with identity providers (IDPs) such as Active Directory Federation Services, and is also multi-tenant aware, allowing independent configuration for each of a cluster’s Access Zones. 

Federal APL requirements mandate that a system must validate all certificates in a chain up to a trusted CA root certificate. To address this, OneFS 9.5 introduces a common Public Key Infrastructure (PKI) library to issue, maintain, and revoke public key certificates. These certificates provide digital signature and encryption capabilities, using public key cryptography to provide identification and authentication, data integrity, and confidentiality. This PKI library is used by all OneFS components that need PKI certificate verification support, such as SecureSMTP, ensuring that they all meet Federal PKI requirements. 

This new OneFS 9.5 PKI and certificate authority infrastructure enables multi-factor authentication, allowing users to swipe a CAC or PIV smartcard containing their login credentials to gain access to a cluster, rather than manually entering username and password information. Additional account policy restrictions in OneFS 9.5 automatically disable inactive accounts, provide concurrent administrative session limits, and implement a delay after a failed login.  

As part of FIPS 140-2 compliance, OneFS 9.5 introduces a new key manager, providing a secure central repository for secrets such as machine passwords, Kerberos keytabs, and other credentials, with the option of using MCF (modular crypt format) with SHA256 or SHA512 hash types. OneFS protocols and services may be configured to support FIPS 140-2 data-in-flight encryption compliance, while SED clusters and the new Master Key re-key capability provide FIPS 140-2 data-at-rest encryption. Plus, any unused or non-compliant services are easily disabled.  

On the network side, the Federal APL has several IPv6 (USGv6) requirements that are focused on allowing granular control of individual components of a cluster’s IPv6 stack, such as duplicate address detection (DAD) and link local IP control. Satisfying both STIG and APL requirements, the new OneFS 9.5 front-end firewall allows security admins to restrict the management interface to specified subnet and implement port blocking and packet filtering rules from the cluster’s command line or WebUI, in accordance with federal or corporate security policy. 

Improving performance for the most demanding workloads

OneFS 9.5 unlocks dramatic performance gains, particularly for the all-flash NVMe platforms, where the PowerScale F900 can now support line-rate streaming reads. SmartCache enhancements allow OneFS 9.5 to deliver streaming read performance gains of up to 55% on the F-series nodes, F600 and F900³, delivering benefit to media and entertainment workloads, plus AI, machine learning, deep learning, and more. 

Enhancements to SmartPools in OneFS 9.5 introduce configurable transfer limits. These limits include maximum capacity thresholds, expressed as a percentage, above which SmartPools will not attempt to move files to a particular tier, boosting both reliability and tiering performance. 

Granular cluster performance control is enabled with the debut of PowerScale SmartQoS, which allows admins to configure limits on the maximum number of protocol operations that NFS, S3, SMB, or mixed protocol workloads can consume. 

Enhancing enterprise-grade supportability and serviceability

OneFS 9.5 enables SupportAssist, Dell’s next generation remote connectivity system for transmitting events, logs, and telemetry from a PowerScale cluster to Dell Support. SupportAssist provides a full replacement for ESRS, as well as enabling Dell Support to perform remote diagnosis and remediation of cluster issues. 

Upgrading to OneFS 9.5 

The new OneFS 9.5 code is available on the Dell Technologies Support site, as both an upgrade and reimage file, allowing both installation and upgrade of this new release.  

Author: Nick Trimbee

In addition to the /usr/bin/isi_gather_info tool, OneFS also provides both a GUI and a common ‘isi’ CLI version of the tool – albeit with slightly reduced functionality. This means that a OneFS log gather can be initiated either from the WebUI, or by using the ‘isi diagnostics’ CLI command set with the following syntax:

# isi diagnostics gather start

The diagnostics gather status can also be queried as follows:

# isi diagnostics gather status
Gather is running.

When the command has completed, the gather tarfile can be found under /ifs/data/Isilon_Support.

You can also view and modify the ‘isi diagnostics’ configuration as follows:

# isi diagnostics gather settings view
                Upload: Yes
                  ESRS: Yes
         Supportassist: Yes
           Gather Mode: full
  HTTP Insecure Upload: No
      HTTP Upload Host:
      HTTP Upload Path:
     HTTP Upload Proxy:
HTTP Upload Proxy Port: -
            Ftp Upload: Yes
       Ftp Upload Host: ftp.isilon.com
       Ftp Upload Path: /incoming
      Ftp Upload Proxy:
 Ftp Upload Proxy Port: -
       Ftp Upload User: anonymous
   Ftp Upload Ssl Cert:
   Ftp Upload Insecure: No

The configuration options for the ‘isi diagnostics gather’ CLI command include:

As mentioned above, ‘isi diagnostics gather’ does not present quite as broad an array of features as the isi_gather_info utility. This is primarily for security purposes, because ‘isi diagnostics’ does not require root privileges to run. Instead, a user account with the ‘ISI_PRIV_SYS_SUPPORT’ RBAC privilege is needed in order to run a gather from either the WebUI or ‘isi diagnostics gather’ CLI interface.

When a gather is running, a second instance cannot be started from any other node until that instance finishes. Typically, a warning similar to the following appears:

"It appears that another instance of gather is running on the cluster somewhere. If you would like to force gather to run anyways, use the --force-multiple-igi flag. If you believe this message is in error, you may delete the lock file here: /ifs/.ifsvar/run/gather.node."

You can remove this lock as follows:

# rm -f /ifs/.ifsvar/run/gather.node

You can also initiate a log gather from the OneFS WebUI by navigating to Cluster management > Diagnostics > Gather:

The WebUI also uses the ‘isi diagnostics’ platform API handler and so, like the CLI command, also offers a subset of the full isi_gather_info functionality.

A limited menu of configuration options is also available in the WebUI, under Cluster management > Diagnostics > Gather settings:

Also contained within the OneFS diagnostics command set is the ‘isi diagnostics netlogger’ utility. Netlogger captures IP traffic over a period of time for network and protocol analysis.

Under the hood, netlogger is a Python wrapper around the ubiquitous tcpdump utility, and can be run either from the OneFS command line or WebUI.

For example, from the WebUI, browse to Cluster management > Diagnostics > Netlogger:

Alternatively, from the OneFS CLI, the isi_netlogger command captures traffic on the interface (‘–interfaces’) over a timeout period of minutes (‘–duration’), and stores a specified number of log files (‘–count’).

Here’s the basic syntax of the CLI utility:

 # isi diagnostics netlogger start
        [--interfaces <str>]
        [--count <integer>]
        [--duration <duration>]
        [--snaplength <integer>]
        [--nodelist <str>]
        [--clients <str>]
        [--ports <str>]
        [--protocols (ip | ip6 | arp | tcp | udp)]
        [{--help | -h}]

Note that using the ‘-b’ bpf buffer size option will temporarily change the default buffer size while netlogger is running.

To display help text for netlogger command options, specify 'isi diagnostics netlogger start -h'. The command options include:

Netlogger’s log files are stored by default under /ifs/netlog/<node_name>.

You can also use the WebUI to configure the netlogger parameters under Cluster management > Diagnostics > Netlogger settings:

Be aware that specifying ‘isi diagnostics netlogger’ can consume significant cluster resources. When running the tool on a production cluster, be aware of the effect on the system.

When the command has completed, the capture file(s) are stored under:

# /ifs/netlog/[nodename]

You can also use the following command to incorporate netlogger output files into a gather_info bundle:

# isi_gather_info -n [node#] -f /ifs/netlog

To capture on multiple nodes of the cluster, you can prefix the netlogger command by the versatile isi_for_array utility. For example:

# isi_for_array –s ‘isi diagnostics netlogger --nodelist 2,3 --timeout 5 --snaplength 256’

This command syntax creates five minute incremental files on nodes 2 and 3, using a snaplength of 256 bytes, which captures the first 256 bytes of each packet. These five-minute logs are kept for about three days. The naming convention is of the form netlog-<node_name>-<date>-<time>.pcap. For example:

# ls /ifs/netlog/tme_h700-1
netlog-tme_h700-1.2022-09-02_10.31.28.pcap

When using netlogger, set the ‘–snaplength’ option appropriately, depending on the protocol, in order to capture the right amount of detail in the packet headers and/or payload. Or, if you want the entire contents of every packet, use a value of zero (‘–snaplength 0’).

The default snaplength for netlogger is to capture 320 bytes per packet, which is typically sufficient for most protocols.

However, for SMB, a snaplength of 512 is sometimes required. Note that depending on a node’s traffic quantity, a snaplength of 0 (that is: capture whole packet) can potentially overwhelm the network interface driver.

All the output gets written to files under /ifs/netlog directory, and the default capture time is ten minutes (‘–duration 10’).

You can apply filters to constrain traffic to/from certain hosts or protocols. For example, to limit output to traffic between client 10.10.10.1 and the cluster node:

# isi diagnostics netlogger --duration 5 --snaplength 256 --clients 10.10.10.1

Or to capture only NFS traffic, filter on port 2049:

# isi diagnostics netlogger --ports 2049

Author: Nick Trimbee

The previous blog outlining the investigation and troubleshooting of OneFS deadlocks and hang-dumps generated several questions about OneFS logfile gathering. So it seemed like a germane topic to explore in an article.

The OneFS ‘isi_gather_info’  utility has long been a cluster staple for collecting and collating context and configuration that primarily aids support in the identification and resolution of bugs and issues. As such, it is arguably OneFS’ primary support tool and, in terms of actual functionality, it performs the following roles:

1. Executes many commands, scripts, and utilities on cluster, and saves their results
2. Gathers all these files into a single ‘gzipped’ package.
3. Transmits the gather package back to Dell, using several optional transport methods.

By default, a log gather tarfile is written to the /ifs/data/Isilon_Support/pkg/ directory. It can also be uploaded to Dell using the following means:

More specifically, the ‘isi_gather_info’ CLI command syntax includes the following options:

When the gather arrives at Dell, it is automatically unpacked by a support process and analyzed using the ‘logviewer’ tool.

Under the hood, there are two principal components responsible for running a gather. These are:

The ‘isi_gather_info’ utility is primarily written in Python, with its configuration under the purview of MCP, and RPC services provided by the isi_rpc_d daemon.

For example:

# isi_gather_info&
# ps -auxw | grep -i gather
root   91620    4.4  0.1 125024  79028  1  I+   16:23        0:02.12 python /usr/bin/isi_gather_info (python3.8)
root   91629    3.2  0.0  91020  39728  -  S    16:23        0:01.89 isi_rpc_d: isi.gather.minion.minion.GatherManager (isi_rpc_d)
root   93231    0.0  0.0  11148   2692  0  D+   16:23        0:00.01 grep -i gather

The overlord uses isi_rdo (the OneFS remote command execution daemon) to start up the minion processes and informs them of the commands to be executed by an ephemeral XML file, typically stored at /ifs/.ifsvar/run/<uuid>-gather_commands.xml. The minion then spins up an executor and a command for each entry in the XML file.

The parallel process executor (the default one to use) acts as a pool, triggering commands to run in parallel until a specified number are running in parallel. The commands themselves take care of the running and processing of results, checking frequently to ensure that the timeout threshold has not been passed.

The executor also keeps track of which commands are currently running, and how many are complete, and writes them to a file so that the overlord process can display useful information. When this is complete, the executor returns the runtime information to the minion, which records the benchmark file. The executor will also safely shut itself down if the isi_gather_info lock file disappears, such as if the isi_gather_info process is killed.

During a gather, the minion returns nothing to the overlord process, because the output of its work is written to disk.

Architecturally, the ‘gather’ process comprises an eight phase workflow:

The details of each phase are as follows:

Because the isi_gather_info tool is primarily intended for troubleshooting clusters with issues, it runs as root (or compadmin in compliance mode), because it needs to be able to execute under degraded conditions (that is, without GMP, during upgrade, and under cluster splits, and so on). Given these atypical requirements, isi_gather_info is built as a stand-alone utility, rather than using the platform API for data collection.

The time it takes to complete a gather is typically determined by cluster configuration, rather than size. For example, a gather on a small cluster with a large number of NFS shares will take significantly longer than on large cluster with a similar NFS configuration. Incremental gathers are not recommended, because the base that’s required to check against in the log store may be deleted. By default, gathers only persist for two weeks in the log processor.

On completion of a gather, a tar’d and zipped logset is generated and placed under the cluster’s /ifs/data/IsilonSupport/pkg directory by default. A standard gather tarfile unpacks to the following top-level structure:

# du -sh *
536M    IsilonLogs-powerscale-f900-cl1-20220816-172533-3983fba9-3fdc-446c-8d4b-21392d2c425d.tgz
320K    benchmark
 24K    celog_events.xml
 24K    command_line
128K    complete
449M    local
 24K    local.log
 24K    nodes_info
 24K    overlord.log
 83M    powerscale-f900-cl1-1
 24K    powerscale-f900-cl1-1.log
119M    powerscale-f900-cl1-2
 24K    powerscale-f900-cl1-2.log
134M    powerscale-f900-cl1-3
 24K    powerscale-f900-cl1-3.log

In this case, for a three node F900 cluster, the compressed tarfile is 536 MB in size. The bulk of the data, which is primarily CLI command output, logs, and sysctl output, is contained in the ‘local’ and individual node directories (powerscale-f900-cl1-*). Each node directory contains a tarfile, varlog.tar, containing all the pertinent logfiles for that node.

The root directory of the tarfile file includes the following:

Notable contents of the ‘local’ directory (all the cluster-wide commands that are executed on the node running the gather) include:

Contents of the directory for the ‘node’ directory include:

As the isi_gather_info command runs, status is provided in the interactive CLI session:

# isi_gather_info
Configuring
    COMPLETE
running local commands
    IN PROGRESS \
Progress of local
[########################################################  ]
147/152 files written  \
Some active commands are: ifsvar_modules_jobengine_cp, isi_statistics_heat, ifsv
ar_modules

When the gather has completed, the location of the tarfile on the cluster itself is reported as follows:

# isi_gather_info
Configuring
    COMPLETE
running local commands
    COMPLETE
running node commands
    COMPLETE
collecting files
    COMPLETE
generating package_info.xml
    COMPLETE
tarring gather
    COMPLETE
uploading gather
    COMPLETE

The path to the tar-ed gather is:

/ifs/data/Isilon_Support/pkg/IsilonLogs-h5001-20220830-122839-23af1154-779c-41e9-b0bd-d10a026c9214.tgz

If the gather upload services are unavailable, errors are displayed on the console, as shown here:

…
uploading gather
    FAILED
        ESRS failed - ESRS has not been provisioned
        FTP failed - pycurl error: (28, 'Failed to connect to ftp.isilon.com port 21 after 81630 ms: Operation timed out')

Author: Nick Trimbee

As we’ve seen in prior articles in this series, OneFS and the PowerScale platforms support a variety of Ethernet speeds, cable and connector styles, and network interface counts, depending on the node type selected. However, unlike the back-end network, Dell Technologies does not specify particular front-end switch models, allowing PowerScale clusters to seamlessly integrate into the data link layer (layer 2) of an organization’s existing Ethernet IP network infrastructure. For example:

A layer 2 looped topology, as shown here, extends VLANs between the distribution/aggregation switches, with spanning tree protocol (STP) preventing network loops by shutting down redundant paths. The access layer uplinks can be used to load balance VLANs. This distributed architecture allows the cluster’s external network to connect to multiple access switches, affording each node similar levels of availability, performance, and management properties.

Link aggregation can be used to combine multiple Ethernet interfaces into a single link-layer interface, and is implemented between a single switch and a PowerScale node, where transparent failover or switch port redundancy is required. Link aggregation assumes that all links are full duplex, point to point, and at the same data rate, providing graceful recovery from link failures. If a link fails, traffic is automatically sent to the next available link without disruption.

Quality of service (QoS) can be implemented through differentiated services code point (DSCP), by specifying a value in the packet header that maps to an ‘effort level’ for traffic. Because OneFS does not provide an option for tagging packets with a specified DSCP marking, the recommended practice is to configure the first hop ports to insert DSCP values on the access switches connected to the PowerScale nodes. OneFS does however retain headers for packets that already have a specified DSCP value.

When designing a cluster, the recommendation is that each node have at least one front-end interface configured, preferably in at least one static SmartConnect zone. Although a cluster can be run in a ‘not all nodes on the network’ (NANON) configuration, where feasible, the recommendation is to connect all nodes to the front-end network(s). Additionally, cluster services such as SNMP, ESRS, ICAP, and auth providers (AD, LDAP, NIS, and so on) prefer that each node have an address that can reach the external servers.

In contrast with scale-up NAS platforms that use separate network interfaces for out-of-band management and configuration, OneFS traditionally performs all cluster network management in-band. However, PowerScale nodes typically contain a dedicated 1Gb Ethernet port that can be configured for use as a management network by ICMP or iDRAC, simplifying administration of a large cluster. OneFS also supports using a node’s serial port as an RS-232 out-of-band management interface. This practice is highly recommended for large clusters. Serial connectivity can provide reliable BIOS-level command line access for on-site or remote service staff to perform maintenance, troubleshooting, and installation operations.

SmartConnect provides a configurable allocation method for each IP address pool:

The default ‘static’ allocation assigns a single persistent IP address to each interface selected in the pool, leaving additional pool IP addresses unassigned if the number of addresses exceeds the total interfaces.

The lowest IP address of the pool is assigned to the lowest Logical Node Number (LNN) from the selected interfaces. The same is true for the second-lowest IP address and LNN, and so on. If a node or interface becomes unavailable, this IP address does not move to another node or interface. Also, when the node or interface becomes unavailable, it is removed from the SmartConnect zone, and new connections will not be assigned to the node. When the node is available again, SmartConnect automatically adds it back into the zone and assigns new connections.

By contrast, ‘dynamic’ allocation divides all available IP addresses in the pool across all selected interfaces. OneFS attempts to assign the IP addresses as evenly as possible. However, if the interface-to-IP address ratio is not an integer value, a single interface might have more IP addresses than another. As such, wherever possible, ensure that all the interfaces have the same number of IP addresses.

In concert with dynamic allocation, dynamic failover provides high availability by transparently migrating IP addresses to another node when an interface is not available. If a node becomes unavailable, all the IP addresses it was hosting are reallocated across the new set of available nodes in accordance with the configured failover load-balancing policy. The default IP address failover policy is round robin, which evenly distributes IP addresses from the unavailable node across available nodes. Because the IP address remains consistent, irrespective of the node on which it resides, failover to the client is transparent, so high availability is seamless.

The other available IP address failover policies are the same as the initial client connection balancing policies, that is, connection count, throughput, or CPU usage. In most scenarios, round robin is not only the best option but also the most common. However, the other failover policies are available for specific workflows.

The decision on whether to implement dynamic failover depends on the protocol(s) being used, general workflow attributes, and any high-availability design requirements:

Assigning each workload or data store to a unique IP address enables OneFS SmartConnect to move each workload to one of the other interfaces. This minimizes the additional work that a remaining node in the SmartConnect pool must absorb and ensures that the workload is evenly distributed across all the other nodes in the pool.

Static IP pools require one IP address for each logical interface within the pool. Because each node provides two interfaces for external networking, if link aggregation is not configured, this would require 2*N IP addresses for a static pool.

Determining the number of IP addresses within a dynamic allocation pool varies depending on the workflow, node count, and the estimated number of clients that would be in a failover event. While dynamic pools need, at a minimum, the number of IP addresses to match a pool’s node count, the ‘N * (N – 1)’ formula can often prove useful for calculating the required number of IP addresses for smaller pools. In this equation, N is the number of nodes that will participate in the pool.

For example, a SmartConnect pool with four-node interfaces, using the ‘N * (N – 1)’ model will result in three unique IP addresses being allocated to each node. A failure on one node interface will cause each of that interface’s three IP addresses to fail over to a different node in the pool. This ensures that each of the three active interfaces remaining in the pool receives one IP address from the failed node interface. If client connections to that node are evenly balanced across its three IP addresses, SmartConnect will evenly distribute the workloads to the remaining pool members. For larger clusters, this formula may not be feasible due to the sheer number of IP addresses required.

Enabling jumbo frames (Maximum Transmission Unit set to 9000 bytes) typically yields improved throughput performance with slightly reduced CPU usage than when using standard frames, where the MTU is set to 1500 bytes. For example, with 40 Gb Ethernet connections, jumbo frames provide about five percent better throughput and about one percent less CPU usage.

OneFS provides the ability to optimize storage performance by designating zones to support specific workloads or subsets of clients. Different network traffic types can be segregated on separate subnets using SmartConnect pools.

For large clusters, partitioning the cluster’s networking resources and allocating bandwidth to each workload can help minimize the likelihood that heavy traffic from one workload will affect network throughput for another. This is particularly true for SyncIQ replication and NDMP backup traffic, which can frequently benefit from its own set of interfaces, separate from user and client IO load.

The ‘groupnet’ networking object is part of OneFS’ support for multi-tenancy. Groupnets sit above subnets and pools and allow separate Access Zones to contain distinct DNS settings.

The management and data network(s) can then be incorporated into different Access Zones, each with their own DNS, directory access services, and routing, as appropriate.

Author: Nick Trimbee

A key decision for performance, particularly in a large cluster environment, is the type and quantity of nodes deployed. Heterogeneous clusters can be architected with a wide variety of node styles and capacities, to meet the needs of a varied data set and a wide spectrum of workloads. These node styles encompass several hardware generations, and fall loosely into three main categories or tiers. While heterogeneous clusters can easily include many hardware classes and configurations, the best practice of simplicity for building clusters holds true here too.

Consider the physical cluster layout and environmental factors, particularly when designing and planning a large cluster installation. These factors include:

• Redundant power supply
• Airflow and cooling
• Rackspace requirements
• Floor tile weight constraints
• Networking requirements
• Cabling distance limitations

The following table details the physical dimensions, weight, power draw, and thermal properties for the range of PowerScale F-series all-flash nodes:

Note that the table above represents individual nodes. A minimum of three similar nodes are required for a node pool.

Similarly, the following table details the physical dimensions, weight, power draw, and thermal properties for the range of PowerScale chassis-based platforms:

Note that this table represents 4RU chassis, each of which contains four PowerScale platform nodes (the minimum node pool size).

The following figure shows the locations of both the front-end (ext-1 & ext-2) and back-end (int-1 & int-2) network interfaces on the PowerScale stand-alone F-series and chassis-based nodes:

A PowerScale cluster’s back-end network is analogous to a distributed systems bus. Each node has two back-end interfaces for redundancy that run in an active/passive configuration (int-1 and int-2 above). The primary interface is connected to the primary switch; the secondary interface is connected to a separate switch.

For nodes using 40/100 Gb or 25/10 Gb Ethernet or InfiniBand connected with multimode fiber, the maximum cable length is 150 meters. This allows a cluster to span multiple rack rows, floors, and even buildings, if necessary. While this can solve floor space challenges, in order to perform any physical administration activity on nodes, you must know where the equipment is located.

The following table shows the various PowerScale node types and their respective back-end network support. While Ethernet is the preferred medium – particularly for large PowerScale clusters – InfiniBand is also supported for compatibility with legacy Isilon clusters.

Currently only Dell Technologies approved switches are supported for back-end Ethernet and IB cluster interconnection. These include:

Be aware that the use of patch panels is not supported for PowerScale cluster back-end connections, regardless of overall cable lengths. All connections must be a single link, single cable directly between the node and back-end switch. Also, Ethernet and InfiniBand switches must not be reconfigured or used for any traffic beyond a single cluster.

Support for leaf spine back-end Ethernet network topologies was first introduced in OneFS 8.2. In a leaf-spine network switch architecture, the PowerScale nodes connect to leaf switches at the access, or leaf, layer of the network. At the next level, the aggregation and core network layers are condensed into a single spine layer. Each leaf switch connects to each spine switch to ensure that all leaf switches are no more than one hop away from one another. For example:

Leaf-to-spine switch connections require even distribution, to ensure the same number of spine connections from each leaf switch. This helps minimize latency and reduces the likelihood of bottlenecks in the back-end network. By design, a leaf spine network architecture is both highly scalable and redundant.

Leaf spine network deployments can have a minimum of two leaf switches and one spine switch. For small to medium clusters in a single rack, the back-end network typically uses two redundant top-of-rack (ToR) switches, rather than implementing a more complex leaf-spine topology.

Author: Nick Trimbee

When it comes to physically installing PowerScale nodes, most use a 35 inch depth chassis and will fit in a standard depth data center cabinet. Nodes can be secured to standard storage racks with their sliding rail kits, included in all node packaging and compatible with racks using either 3/8 inch square holes, 9/32 inch round holes, or 10-32 / 12-24 / M5X.8 / M6X1 pre-threaded holes. These supplied rail kit mounting brackets are adjustable in length, from 24 inches to 36 inches, to accommodate different rack depths. When selecting an enclosure for PowerScale nodes, ensure that the rack supports the minimum and maximum rail kit sizes.

However, the high-capacity models, such as the F800/810, H7000, H5600, A3000 and A2000, have 40 inch depth chassis and require extended depth cabinets, such as the APC 3350 or Dell Titan-HD rack.

Additional room must be provided for opening the FRU service trays at the rear of the nodes and, in the chassis-based 4RU platforms, the disk sleds at the front of the chassis. Except for the 2RU F900, the stand-alone PowerScale all-flash nodes are 1RU in height (including the 1RU diskless P100 accelerator and B100 backup accelerator nodes).

Power-wise, each cabinet typically requires between two and six independent single or three-phase power sources. To determine the specific requirements, use the published technical specifications and device rating labels for the devices to calculate the total current draw for each rack.

Additionally, the recommended environmental conditions to support optimal PowerScale cluster operation are as follows:

Weight is a critical factor to keep in mind, particularly with the chassis-based nodes. Individual 4RU chassis can weigh up to around 300 lbs each, and the maximum floor tile capacity for each individual cabinet or rack must be kept in mind. For the deep node styles (H7000, H5600, A3000 and A2000), the considerable node weight may prevent racks from being fully populated with PowerScale equipment. If the cluster uses a variety of node types, installing the larger, heavier nodes at the bottom of each rack and the lighter chassis at the top can help distribute weight evenly across the cluster racks’ floor tiles.

Note that there are no lift handles on the PowerScale 4RU chassis. However, the drive sleds can be removed to provide handling points if no lift is available. With all the drive sleds removed, but leaving the rear compute modules inserted, the chassis weight drops to a more manageable 115 lbs or so. It is strongly recommended to use a lift for installation of 4RU chassis.

Cluster back-end switches ship with the appropriate rails (or tray) for proper installation of the switch in the rack. These rail kits are adjustable to fit NEMA front rail to rear rail spacing ranging from 22 in to 34 in.

Note that some manufacturers’ Ethernet switch rails are designed to overhang the rear NEMA rails, helping to align the switch with the PowerScale chassis at the rear of the rack. These require a minimum clearance of 36 in from the front NEMA rail to the rear of the rack, in order to ensure that the rack door can be closed.

Consider the following large cluster topology, for example:

This contiguous rack architecture is designed to scale up to the current maximum PowerScale cluster size of 252 nodes, in 63 4RU chassis, across nine racks as the environment grows – while still keeping cable management relatively simple. Note that this configuration assumes 1RU per node. If you are using F900 nodes, which are 2RU in size, be sure to budget for additional rack capacity.

Successful large cluster infrastructures depend on the proficiency of the installer and their optimizations for maintenance and future expansion. Some good data center design practices include:

• Pre-allocating and reserving adjacent racks in the same isle to accommodate the anticipated future cluster expansion
• Reserving an empty ‘mailbox’ slot in the top half of each rack for any pass-through cable management needs
• Dedicating one of the racks in the group for the back-end and front-end distribution/spine switches – in this case rack R3

For Hadoop workloads, PowerScale clusters are compatible with the rack awareness feature of HDFS to provide balancing in the placement of data. Rack locality keeps the data flow internal to the rack.

Excess cabling can be neatly stored in 12” service coils on a cable tray above the rack, if available, or at the side of the rack as illustrated below.

The use of intelligent power distribution units (PDUs) within each rack can facilitate the remote power cycling of nodes, if desired.

For deep nodes such as the H7000 and A3000 hardware, where chassis depth can be a limiting factor, horizontally mounted PDUs within the rack can be used in place of vertical PDUs, if necessary. If front-mounted, partial depth Ethernet switches are deployed, you can install horizontal PDUs in the rear of the rack directly behind the switches to maximize available rack capacity.

With copper cables (such as SFP+, QSFP, CX4), the maximum cable length is typically limited to 10 meters or less. After factoring in for dressing the cables to maintain some level of organization and proximity within the racks and cable trays, all the racks with PowerScale nodes need to be near each other – either in the same rack row or close by in an adjacent row – or adopt a leaf-spine topology, with leaf switches in each rack.

If greater physical distance between nodes is required, support for multimode fiber (QSFP+, MPO, LC, etc) extends the cable length limitation to 150 meters. This allows nodes to be housed on separate floors or on the far side of a floor in a datacenter if necessary. While solving the floor space problem, this does have the potential to introduce new administrative and management challenges.

The following table lists the various cable types, form factors, and supported lengths available for PowerScale nodes:

The connector types for the cables above can be identified as follows:

As for the nodes themselves, the following rear views indicate the locations of the various network interfaces:

Note that Int-a and int-b indicate the primary and secondary back-end networks, whereas Ext-1 and Ext-2 are the front-end client networks interfaces.

Be aware that damage to the InfiniBand or Ethernet cables (copper or optical fiber) can negatively affect cluster performance. Never bend cables beyond the recommended bend radius, which is typically 10–12 times the diameter of the cable. For example, if a cable is 1.6 inches, round up to 2 inches and multiply by 10 for an acceptable bend radius.

Cables differ, so follow the explicit recommendations of the cable manufacturer.

The most important design attribute for bend radius consideration is the minimum mated cable clearance (Mmcc). Mmcc is the distance from the bulkhead of the chassis through the mated connectors/strain relief including the depth of the associated 90 degree bend. Multimode fiber has many modes of light (fiber optic) traveling through the core. As each of these modes moves closer to the edge of the core, light and the signal are more likely to be reduced, especially if the cable is bent. In a traditional multimode cable, as the bend radius is decreased, the amount of light that leaks out of the core increases, and the signal decreases. Best practices for data cabling include:

• Keep cables away from sharp edges or metal corners.
• Avoid bundling network cables with power cables. If network and power cables are not bundled separately, electromagnetic interference (EMI) can affect the data stream.
• When bundling cables, do not pinch or constrict the cables.
• Avoid using zip ties to bundle cables. Instead use Velcro hook-and-loop ties that do not have hard edges, and can be removed without cutting. Fastening cables with Velcro ties also reduces the impact of gravity on the bend radius.

Note that the effects of gravity can also decrease the bend radius and result in degradation of signal power and quality.

Cables, particularly when bundled, can also obstruct the movement of conditioned air around the cluster, and cables should be secured away from fans. Flooring seals and grommets can be useful to keep conditioned air from escaping through cable holes. Also ensure that smaller Ethernet switches are drawing cool air from the front of the rack, not from inside the cabinet. This can be achieved either with switch placement or by using rack shelving.

Author: Nick Trimbee

In this article, we turn our attention to some of the environmental and logistical aspects of cluster design, installation, and management.

In addition to available rack space and physical proximity of nodes, provision needs to be made for adequate power and cooling as the cluster expands. New generations of drives and nodes typically deliver increased storage density, which often magnifies the power draw and cooling requirements per rack unit.

The recommendation is for a large cluster’s power supply to be fully redundant and backed up with a battery UPS and/or power generator. In the worst instance, if a cluster does loose power, the nodes are protected internally by filesystem journals which preserve any in-flight uncommitted writes. However, the time to restore power and bring up a large cluster from an unclean shutdown can be considerable.

Like most data center equipment, the cooling fans in PowerScale nodes and switches pull air from the front to back of the chassis. To complement this, data centers often employ a hot isle/cold isle rack configuration, where cool, low humidity air is supplied in the aisle at the front of each rack or cabinet either at the floor or ceiling level, and warm exhaust air is returned at ceiling level in the aisle to the rear of each rack.

Given the significant power draw, heat density, and weight of cluster hardware, some datacenters are limited in the number of nodes each rack can support. For partially filled racks, the use of blank panels to cover the front and rear of any unfilled rack units can help to efficiently direct airflow through the equipment.

The table below shows the various front and back-end network speeds and connector form factors across the PowerScale storage node portfolio.

With large clusters, especially when the nodes may not be racked in a contiguous manner, it is highly advised to have all the nodes and switches connected to serial console concentrators and remote power controllers. However, to perform any physical administration or break/fix activity on nodes, you must know where the equipment is located and have administrative resources available to access and service all locations.

As such, the following best practices are recommended:

• Develop and update thorough physical architectural documentation.
• Implement an intuitive cable coloring standard.
• Be fastidious and consistent about cable labeling.
• Use the appropriate length of cable for the run and create a neat 12” loop of any excess cable, secured with Velcro.
• Observe appropriate cable bend ratios, particularly with fiber cables.
• Dress cables and maintain a disciplined cable management ethos.
• Keep a detailed cluster hardware maintenance log.
• Where appropriate, maintain a ‘mailbox’ space for cable management.

Disciplined cable management and labeling for ease of identification is particularly important in larger PowerScale clusters, where density of cabling is high. Each chassis can require up to 28 cables, as shown in the following table:

The recommendations for cabling a PowerScale chassis are:

• Split cabling in the middle of the chassis, between nodes 2 and 3.
• Route Ethernet and Infiniband cables towards the lower side of the chassis.
• Connect power cords for nodes 1 and 3 to PDU A, and power cords for nodes 2 and 4 to PDU B.
• Bundle network cables with the AC power cords for ease of management.
• Leave enough cable slack for servicing each individual node’s FRUs.

Similarly, the stand-alone F-series all flash nodes, in particular the 1RU F600 and F200 nodes, also have a similar density of cabling per rack unit:

Consistent and meticulous cable labeling and management is particularly important in large clusters. PowerScale chassis that employ both front and back-end Ethernet networks can include up to 20 Ethernet connections per 4RU chassis.

In each node’s compute module, there are two PCI slots for the Ethernet cards (NICs). Viewed from the rear of the chassis, in each node the right hand slot (HBA Slot 0) houses the NIC for the front-end network, and the left hand slot (HBA Slot 1) houses the NIC for the front-end network. There is also a separate built-in 1Gb Ethernet port on each node for cluster management traffic.

While there is no requirement that node 1 aligns with port 1 on each of the back-end switches, it can certainly make cluster and switch management and troubleshooting considerably simpler. Even if exact port alignment is not possible, with large clusters, ensure that the cables are clearly labeled and connected to similar port regions on the back-end switches.

PowerScale nodes and the drives they contain have identifying LED lights to indicate when a component has failed and to allow proactive identification of resources. You can use the ‘isi led’ CLI command to illuminate specific node and drive indicator lights, as needed, to aid in identification.

Drive repair times depend on a variety of factors:

• OneFS release (determines Job Engine version and how efficiently it operates)
• System hardware (determines drive types, amount of CPU, RAM, and so on)
• Filesystem: Amount of data, data composition (lots of small vs large files), protection, tunables, and so on.
• Load on the cluster during the drive failure

A useful method to estimate future FlexProtect runtime is to use old repair runtimes as a guide, if available.

The drives in the PowerScale chassis-based platforms have a bay-grid nomenclature, where A-E indicates each of the sleds and 0-6 would point to the drive position in the sled. The drive closest to the front is 0, whereas the drive closest to the back is 2/3/5, depending on the drive sled type.

When it comes to updating and refreshing hardware in a large cluster, swapping nodes can be a lengthy process of somewhat unpredictable duration. Data has to be evacuated from each old node during the Smartfail process prior to its removal, and restriped and balanced across the new hardware’s drives. During this time there will also be potentially impactful group changes as new nodes are added and the old ones removed.

However, if replacing an entire node-pool as part of a tech refresh, a SmartPools filepool policy can be crafted to migrate the data to another nodepool across the back-end network. When complete, the nodes can then be Smartfailed out, which should progress swiftly because they are now empty.

If multiple nodes are Smartfailed simultaneously, at the final stage of the process the node remove is serialized with around 60 seconds pause between each. The Smartfail job places the selected nodes in read-only mode while it copies the protection stripes to the cluster’s free space. Using SmartPools to evacuate data from a node or set of nodes in preparation to remove them is generally a good idea, and is usually a relatively fast process.

Another efficient approach can often be to swap drives out into new chassis. In addition to being considerably faster, the drive swapping process focuses the disruption on a single whole cluster down event. Estimating the time to complete a drive swap, or ‘disk tango’ process, is simpler and more accurate and can typically be completed in a single maintenance window.

With PowerScale chassis-based platforms, such as the H700 and A300, the available hardware ‘tango’ options are expanded and simplified. Given the modular design of these platforms, the compute and chassis tango strategies typically replace the disk tango:

Note that any of the above ‘tango’ procedures should only be executed under the recommendation and supervision of Dell support.

Author: Nick Trimbee

Dell PowerScale, the world’s most secure NAS storage array[1], continues to evolve its already rich security capabilities with the recent introduction of External Key Manager for Data-at-Rest-Encryption, enhancements to the STIG security profile, and support for UEFI Secure Boot across PowerScale platforms. 

Our next release of PowerScale OneFS  adds new security features that include software-based firewall functionality, multi-factor authentication with support for CAC/PIV, SSO for administrative WebUI, and FIPS-compliant data in flight. 

As the PowerScale security feature set continues to advance, meeting the highest level of federal compliance is paramount to support industry and federal security standards. We are excited to announce that our scheduled verification by the Department of Defense Information Network (DISA) for inclusion on the DoD Approved Product List will begin in March 2023. For more information, see the DISA schedule here.

Moreover, OneFS will embrace the move to IPv6-only networks with support for USGv6-r1, a critical network standard applicable to hundreds of federal agencies and to the most security-conscious enterprises, including the DoD. Refreshed Common Criteria certification activities are underway and will provide a highly regarded international and enterprise-focused complement to other standards being supported.

We believe that implementing the zero trust model is the best foundation for building a robust security framework for PowerScale. This model and its principles are discussed below.  

Supercharge Dell PowerScale security with the zero trust model

In the age of digital transformation, multiple cloud providers, and remote employees, the confines of the traditional data center are not enough to provide the highest levels of security. In the traditional sense, security was considered placing your devices in an imaginary “bubble.” The thought was that as long as devices were in the protected “bubble,” security was already accounted for through firewalls on the perimeter. However, the age-old concept of an organization’s security depending on the firewall is no longer relevant and is the easiest for a malicious party to attack.

Now that the data center is not confined to an area, the security framework must evolve, transform, and adapt. For example, although firewalls are still critical to network infrastructure, security must surpass just a firewall and security devices.

Why is data security important?

Although this seems like an easy question, it’s essential to understand the value of what is being protected. Traditionally, an organization’s most valuable assets were its infrastructure, including a building and the assets required to produce its goods. However, in the age of Digital Transformation, organizations have realized that the most critical asset is their data.

Why a zero trust model?

Because data is an organization’s most valuable asset, protecting the data is paramount. And how do we protect this data in the modern environment without data center confines? Enter the zero trust model!

Although Forrester Research first defined zero trust architecture in 2010, it has recently received more attention with the ever-changing security environment leading to a focus on cybersecurity. The zero trust architecture is a general model and must be refined for a specific implementation. For example, in September 2019, the National Institute of Standards and Technology (NIST) introduced its concept of Zero Trust Architecture. As a result, the White House has also published an Executive Order on Improving the Nation’s Cybersecurity, including zero trust initiatives.

In a zero trust architecture, all devices must be validated and authenticated. The concept applies to all devices and hosts, ensuring that none are trusted until proven otherwise. In essence, the model adheres to a “never trust, always verify” policy for all devices.   

NIST Special Publication 800-207 Zero Trust Architecture states that a zero trust model is architected with the following design tenets:

• All data sources and computing services are considered resources.
• All communication is secured regardless of network location.
• Access to individual enterprise resources is granted on a per session basis.
• Access to resources is determined by dynamic policy—including the observable state of client identity, application/service, and the requesting asset—and may include other behavioral and environmental attributes.
• The enterprise monitors and measures the integrity and security posture of all owned and associated assets.
• All resource authentication and authorization are dynamic and strictly enforced before access is allowed.
• The enterprise collects as much information as possible related to the current state of assets, network infrastructure, and communications and uses it to improve its security posture.

PowerScale OneFS follows the zero trust model

The PowerScale family of scale-out NAS solutions includes all-flash, hybrid, and archive storage nodes that can be deployed across the entire enterprise – from the edge, to core, and the cloud, to handle the most demanding file-based workloads. PowerScale OneFS combines the three layers of storage architecture—file system, volume manager, and data protection—into a scale-out NAS cluster. Dell Technologies follows the NIST Cybersecurity Framework to apply zero trust principles on a PowerScale cluster. The NIST Framework identifies five principles: identify, protect, detect, respond, and recover. Combining the framework from the NIST CSF and the data model provides the basis for the PowerScale zero trust architecture in five key stages, as shown in the following figure.

Let’s look at each of these stages and what Dell Technologies tools can be used to implement them.

1. Locate, sort, and tag the dataset

To secure an asset, the first step is to identify the asset. In our case, it is data. To secure a dataset, it must first be located, sorted, and tagged to secure it effectively. This can be an onerous process depending on the number of datasets and their size. We recommend using the Superna Eyeglass Search and Recover feature to understand your unstructured data and to provide insights through a single pane of glass, as shown in the following image. For more information, see the Eyeglass Search and Recover Product Overview.

2. Roles and access

Once we know the data we are securing, the next step is to associate roles to the indexed data. The role-specific administrators and users only have access to a subset of the data necessary for their responsibilities. PowerScale OneFS allows system access to be limited to an administrative role through Role-Based Access Control (RBAC). As a best practice, assign only the minimum required privileges to each administrator as a baseline. In the future, more privileges can be added as needed. For more information, see PowerScale OneFS Authentication, Identity Management, and Authorization.

3. Encryption

For the next step in deploying the zero trust model, use encryption to protect the data from theft and man-in-the-middle attacks.

Data at Rest Encryption

PowerScale OneFS provides Data at Rest Encryption (D@RE) using self-encrypting drives (SEDs), allowing data to be encrypted during writes and decrypted during reads with a 256-bit AES encryption key, referred to as the data encryption key (DEK). Further, OneFS wraps the DEK for each SED in an authentication key (AK). Next, the AKs for each drive are placed in a key manager (KM) that is stored securely in an encrypted database, the key manager database (KMDB). Next, the KMDB is encrypted with a 256-bit master key (MK). Finally, the 256-bit master key is stored external to the PowerScale cluster using a key management interoperability protocol (KMIP)-compliant key manager server, as shown in the following figure. For more information, see PowerScale Data at Rest Encryption.

Data in flight encryption

Data in flight is encrypted using SMB3 and NFS v4.1 protocols. SMB encryption can be used by clients that support SMB3 encryption, including Windows Server 2012, 2012 R2, 2016, Windows 10, and 11. Although SMB supports encryption natively, NFS requires additional Kerberos authentication to encrypt data in flight. OneFS Release 9.3.0.0 supports NFS v4.1, allowing Kerberos support to encrypt traffic between the client and the PowerScale cluster.

Once the protocol access is encrypted, the next step is encrypting data replication. OneFS supports over-the-wire, end-to-end encryption for SyncIQ data replication, protecting and securing in-flight data between clusters. For more information about these features, see the following:

• PowerScale: Solution Design and Considerations for SMB Environments
• PowerScale OneFS NFS Design Considerations and Best Practices
• PowerScale SyncIQ: Architecture, Configuration, and Considerations

4. Cybersecurity

In an environment of ever-increasing cyber threats, cyber protection must be part of any security model. Superna Eyeglass Ransomware Defender for PowerScale provides cyber resiliency. It protects a PowerScale cluster by detecting attack events in real-time and recovering from cyber-attacks. Event triggers create an automated response with real-time access auditing, as shown in the following figure.

The Enterprise AirGap capability creates an isolated data copy in a cyber vault that is network isolated from the production environment, as shown in the following figure. For more about PowerScale Cyber Protection Solution, check out this comprehensive eBook.

5. Monitoring

Monitoring is a critical component of applying a zero trust model. A PowerScale cluster should constantly be monitored through several tools for insights into cluster performance and tracking anomalies. Monitoring options for a PowerScale cluster include the following:

• Dell CloudIQ for proactive monitoring, machine learning, and predictive analytics.
• Superna Ransomware Defender for protecting a PowerScale cluster by detecting attack events in real-time and recovering from cyber-attacks. It also offers AirGap.
• PowerScale OneFS SDK to create custom applications specific to an organization. Uses the OneFS API to configure, manage, and monitor cluster functionality. The OneFS SDK provides greater visibility into a PowerScale cluster.

Conclusion

This blog introduces implementing the zero trust model on a PowerScale cluster. For additional details and applying a complete zero trust implementation, see the PowerScale Zero Trust Architecture section in the Dell PowerScale OneFS: Security Considerations white paper. You can also explore the other sections in this paper to learn more about all PowerScale security considerations.

Author: Aqib Kazi

As a security best practice, a quarterly security review is recommended. Forming an aggressive security posture for a PowerScale cluster is composed of different facets that may not be applicable to every organization. An organization’s industry, clients, business, and IT administrative requirements determine what is applicable. To ensure an aggressive security posture for a PowerScale cluster, use the checklist in the following table as a baseline for security.

This table serves as a security baseline and must be adapted to specific organizational requirements. See the Dell PowerScale OneFS: Security Considerations white paper for a comprehensive explanation of the concepts in the table below.

Further, cluster security is not a single event. It is an ongoing process: Monitor this blog for updates. As new updates become available, this post will be updated. Consider implementing an organizational security review on a quarterly basis.

The items listed in the following checklist are not in order of importance or hierarchy but rather form an aggressive security posture as more features are implemented.

Table 1.  PowerScale security baseline checklist

Author: Aqib Kazi

Object is the new core

Content creation workflows are increasingly distributed between multiple sites and cloud providers. Data orchestration has long been a key component in these workflows. With the extra complexity (and functionality) of multiple on-premises and cloud infrastructures, automated data orchestration is more crucial than ever.

There has been a subtle but significant shift in how media companies store and manage data. In the old way, file storage formed the “core” and data was eventually archived off to tape or object storage for long-term retention. The new way of managing data flips this paradigm. Object storage has become the new “core” with performant file storage at edge locations used for data processing and manipulation.

Various factors have influenced this shift. These factors include the ever-increasing volume of data involved in modern productions, the expanding role of public cloud providers (for whom object storage is the default), and media application support.

Figure 1.  Global storage environment

With this shift in roles, new techniques for data orchestration become necessary. Data management vendors are reacting to these requirements for data movement and global file system solutions.

However, many of these solutions require data to be ingested and accessed through dedicated proprietary gateways. Often this gateway approach means that the data is now inaccessible using the native S3 API.

PowerScale OneFS and Superna Golden Copy provide a way of orchestrating data between file and object that retains the best qualities of both types of storage. Data is available to be accessed on both the performant edge (PowerScale) and the object core (ECS or public cloud) with no lock in at either end.

Further, Superna Golden Copy is directly integrated with the PowerScale OneFS API. The OneFS snapshot change list is used for immediate incremental data moves. Filesystem metadata is preserved in S3 tags.

Golden Copy and OneFS are a solution built for seamless movement of data between locations, file system, and object storage. File structure and metadata are preserved.

Right tool for the job

Data that originates on object storage needs to be accessible natively by systems that can speak object APIs. Also, some subset of data needs to be moved to file storage for further processing. Production data that originates on file storage similarly needs native access. That file data will need to be moved to object storage for long-term retention and to make it accessible to globally distributed resources.

Content creation workflows are spread across multiple teams working in many locations. Multisite productions require distributed storage ecosystems that can span geographies. This architecture is well suited to a core of object storage as the “central source of truth”. Pools of highly performant file storage serve teams in their various global locations.

The Golden Copy GraphQL API allows external systems to control, configure, and monitor Golden Copy jobs. This type of API-based data orchestration is essential to the complex global pipelines of content creators. Manually moving large amounts of data is untenable. Schedule-based movement of data aligns well with some content creation workflows; other workflows require more ad hoc data movement.

 Figure 2.  Object Core with GoldenCopy and PowerScale

A large ecosystem of production management tools, such as Autodesk Shotgrid, exist for managing global teams. These tools are excellent for managing projects, but do not typically include dedicated data movers. Data movement can be particularly challenging when large amounts of media need to be shifted between object and file.

Production asset management can trigger data moves with Golden Copy based on metadata changes to a production or scene. This kind of API and metadata driven data orchestration fits in the MovieLabs 2030 vision for software-defined workflows for content creation. This topic is covered in some detail for tiering within a OneFS file system in the paper: A Metadata Driven Approach to On Demand Tiering.

For more information about using PowerScale OneFS together with Superna GoldenCopy, see my full white paper PowerScale OneFS: Distributed Media Workflows.

Author: Gregory Shiff

AI is a fancy and hot topic in recent years. A common question from our customers is ‘How can AI help the day-to-day operation and management of PowerScale?’ It’s a very interesting question, because although AI can help realize so many possibilities, we still don’t have that many implementations of it in IT infrastructure. 

But, we finally have something that is very inspiring. Here is what we have achieved as proof of concept in our lab with the support of AI Dynamics, a professional AI platform company. 

Challenges for IT operations and opportunities for AIOps

With the increase in complexity of IT infrastructure comes the increase in the amount of data produced by these systems, Real-time performance logs, usage reports, audits, and other metadata can add up to gigabytes or terabytes a day. It is a big challenge for the IT department to analyze this data and to extract proactive predictions, such as IT infrastructure performance issues and their bottlenecks.

AIOps is the methodology to address these challenges. The term ‘AIOps’ refers to the use of artificial intelligence (AI), specifically machine learning (ML) techniques, to ingest, analyze, and learn from large volumes of data from every corner of the IT environment. The goal of AIOps is to allow IT departments to manage their assets and tackle performance challenges proactively, in real-time (or better), before they become system-wide issues. 

PowerScale key performance prediction using AIOps

Overview

In this solution, we identify NFS latency as the PowerScale performance indicator that customers would like to see predictive reporting about. The goal of the AI model is to study historical system activity and predict the NFS latency at five-minute intervals for four hours in the future. A traditional software system can use these predictions to alert users of a potential performance bottleneck based on the user’s specified latency threshold level and spike duration. In the future, AI models can be built that help diagnose the source of these issues so that both an alert and a best-recommended solution can be reported to the user.

The whole training process involves the following three steps (I’ll explain the details in the following sections):

• Data preparation – to get the raw data and extract the useful features as the input for training and validation
• Training the model – to pick up a proper AI architecture and tune the parameters for accuracy
• Model validation – to validate the AI model based on the data set obtained from the training

Data preparation

The raw performance data is collected through Dell Secure Remote Services (SRS) from 12 different all-flash PowerScale clusters from an electronic design automation (EDA) customer each week. We identify and extract 26 performance key metrics from the raw data, most of which are logged and updated every five minutes. AI Dynamics NeoPulse is used to extract some additional fields (such as the day of the week and time of day from the UNIX timestamp fields) to allow the model to make better predictions. Each week new data was collected from the PowerScale cluster to increase the size of the training dataset and to improve the AI model. During every training run, we also withheld 10% of the data, which we used to test the AI model in the testing phase. This is separate from the 10% of training data withheld for validation.

Figure 1.  Data preparation process

Training the model

Over a period of two months, more than 50 different AI models were trained using a variety of different time series architectures, varying model architecture parameters, hyperparameters, and data engineering techniques to maximize performance, without overfitting to existing data. When these training pipelines were created in NeoPulse, they could easily be reused as new data arrived from the client each week, to rerun training and testing in order to quantify the performance of the model.

At the end of the two-month period, we had built a model that could predict whether this one performance metric (NFS3 latency) would be above a threshold of 10ms, correctly for 70% of each one of the next 48 five-minute intervals (four hours total).

Model validation

In the data preparation phase, we withheld 10% of the total data set to be used for AI model validation and testing. With the current AI model, end-users can easily configure the threshold of the latency as they want. In this case, we validated the model at 10ms and 15ms thresholds latency. The model can correctly identify over 70% of 10ms latency spikes and 60% of 15ms latency spikes over the entire ensuing four-hour period.

Figure 2.  Model Validation

Results

In this solution, we used NFS latency from PowerScale as the indicator to be predicted. The AI model uses the performance data from the previous four hours to predict the trends and spikes of NFS latency in the next four hours. If the software identifies a five-minute period when a >10ms latency spike would occur more than 70% of the time, it will trigger a configurable alert to the user.

The following diagram shows an example. At 8:55 a.m., the AI model predicts the NFS latency from 8:55 a.m. to 12:55 p.m., based on the input of performance data from 4:55 a.m. to 8:55 a.m. The AI model makes predictions for each five-minute period over the prediction duration. The model predicts a few isolated spikes in latency, with a large consecutive cluster of high latency between around 12 p.m. and 12:55 p.m. A software system can use this prediction to alert the user about the expected increase in latency, giving them over three hours to get ahead of the problem and reduce the server load. In the graph, the dotted line shows the AI model’s prediction, whereas the solid line shows actual performance.

Figure 3.  Dell PowerScale NFS Latency Forecasting

To sum up, the solution achieved the following:

• By using the previous four hours of PowerScale performance data, the solution can forecast the next four hours of any specified metric.
• For NFS3 latency, the solution was benchmarked as correctly identifying periods when latency would be above 10ms 70% of the time.
• The data and model training pipelines created for this task can easily be adapted to predict other performance metrics, such as NFS throughput spikes, SMB latency spikes, and so on.
• The AI learns to improve its predictions week by week as it adapts to each customer’s nuanced usage patterns, creating customized models for each customer’s idiosyncratic workload profiles.

Conclusion

AIOps introduces the intelligence needed to manage the complexity of modern IT environments. The NeoPulse platform from AI Dynamics makes AIOps easy to implement. In an all-flash configuration of Dell PowerScale clusters, performance is one of the key considerations. Hundreds and thousands of performance logs are generated every day and it is very easy for AIOps to consume the existing logs and provide insight into potential performance bottlenecks. Dell servers with GPUs are great platforms for performing training and inference, for not just this model but for any other new AI challenge the company wishes to tackle, across dozens of problem types.  

For additional details about our testing, see the white paper Key Performance Prediction using Artificial Intelligence for IT operations (AIOps).

Author: Vincent Shen

Network connectivity is an essential part of any infrastructure architecture. When it comes to how Kubernetes connects to PowerScale, there are several options to configure the Container Storage Interface (CSI). In this post, we will cover the concepts and configuration you can implement.

The story starts with CSI plugin architecture.

CSI plugins

Like all other Dell storage CSI, PowerScale CSI follows the Kubernetes CSI standard by implementing functions in two components.

• CSI controller plugin
• CSI node plugin 

The CSI controller plugin is deployed as a Kubernetes Deployment, typically with two or three replicas for high-availability, with only one instance acting as a leader. The controller is responsible for communicating with PowerScale, using Platform API to manage volumes (to PowerScale it’s to create/delete directories, NFS exports, and quotas), to update the NFS client list when a Pod moves, and so on.

A CSI node plugin is a Kubernetes DaemonSet, running on all nodes by default. It’s responsible for mounting the NFS export from PowerScale, to map the NFS mount path to a Pod as persistent storage, so that applications and users in the Pod can access the data on PowerScale.

Roles, privileges, and access zone

Because CSI needs to access both PAPI (PowerScale Platform API) and NFS data, a single user role typically isn’t secure enough: the role for PAPI access will need more privileges than normal users.

According to the PowerScale CSI manual, CSI requires a user that has the following privileges to perform all CSI functions:

Among these privileges, ISI_PRIV_SNAPSHOT and ISI_PRIV_QUOTA are only available in the System zone. And this complicates things a bit. To fully utilize these CSI features, such as volume snapshot, volume clone, and volume capacity management, you have to allow the CSI to be able to access the PowerScale System zone. If you enable the CSM for replication, the user needs the ISI_PRIV_SYNCIQ privilege, which is a System-zone privilege too.

By contrast, there isn’t any specific role requirement for applications/users in Kubernetes to access data: the data is shared by the normal NFS protocol. As long as they have the right ACL to access the files, they are good. For this data accessing requirement, a non-system zone is suitable and recommended.

These two access zones are defined in different places in CSI configuration files:

• The PAPI access zone name (FQDN) needs to be set in the secret yaml file as “endpoint”, for example “f200.isilon.com”.
• The data access zone name (FQDN) needs to be set in the storageclass yaml file as “AzServiceIP”, for example “openshift-data.isilon.com”.

If an admin really cannot expose their System zone to the Kubernetes cluster, they have to disable the snapshot and quota features in the CSI installation configuration file (values.yaml). In this way, the PAPI access zone can be a non-System access zone.

The following diagram shows how the Kubernetes cluster connects to PowerScale access zones.

Network

Normally a Kubernetes cluster comes with many networks: a pod inter-communication network, a cluster service network, and so on. Luckily, the PowerScale network doesn’t have to join any of them. The CSI pods can access a host’s network directly, without going through the Kubernetes internal network. This also has the advantage of providing a dedicated high-performance network for data transfer.

For example, on a Kubernetes host, there are two NICs: IP 192.168.1.x and 172.24.1.x. NIC 192.168.1.x is used for Kubernetes, and is aligned with its hostname. NIC 172.24.1.x isn’t managed by Kubernetes. In this case, we can use NIC 172.24.1.x for data transfer between Kubernetes hosts and PowerScale.

Because by default, the CSI driver will use the IP that is aligned with its hostname, to let CSI recognize the second NIC 172.24.1.x, we have explicitly set the IP range in “allowedNetworks” in the values.yaml file in the CSI driver installation. For example:

allowedNetworks: [172.24.1.0/24]

Also, in this network configuration, it’s unlikely that the Kubernetes internal DNS can resolve the PowerScale FQDN. So, we also have to make sure the “dnsPolicy” has been set to “ClusterFirstWithHostNet” in the values.yaml file. With this dnsPolicy, the CSI pods will reach the DNS server in /etc/resolv.conf in the host OS, not the internal DNS server of Kubernetes.

The following diagram shows the configuration mentioned above:

Please note that the “allowedNetworks” setting only affects the data access zone, and not the PAPI access zone. In fact, CSI just uses this parameter to decide which host IP should be set as the NFS client IP on the PowerScale side.

Regarding the network routing, CSI simply follows the OS route configuration. Because of that, if we want the PAPI access zone to go through the primary NIC (192.168.1.x), and have the data access zone to go through the second NIC (172.24.1.x), we have to change the route configuration of the Kubernetes host, not this parameter.

Hopefully this blog helps you understand the network configuration for PowerScale CSI better. Stay tuned for more information on Dell Containers & Storage!

Authors: Sean Zhan, Florian Coulombel

In today's security environment, organizations must adhere to governance security requirements, including disabling specific HTTP services.

OneFS release 9.4.0.0 has introduced an option to disable non-essential cluster services selectively rather than disabling all HTTP services. Disabling selectively allows administrators to determine which services are necessary. Disabling the services allows other essential services on the cluster to continue to run. You can disable the following non-essential services:

• PowerScaleUI (WebUI)
• Platform-API-External
• Rest Access to Namespace (RAN)
• RemoteService

Each of these services can be disabled independently and has no impact on other HTTP-based data services. The services can be disabled through the CLI or API with the ISI_PRIV_HTTP privilege. To manage the non-essential services from the CLI, use the isi http services list command to list the services. Use the isi http services view and isi http services modify commands to view and modify the services. The impact of disabling each of the services is listed in the following table.

HTTP services impacts

To disable the WebUI, use the following command:

isi http services modify --service-id=PowerScaleUI --enabled=false

Author: Aqib Kazi

PowerScale for Google Cloud provides the native-cloud experience of file services with high performance. It is a scalable file service that provides high-speed file access over multiple protocols, including SMB, NFS, and HDFS. PowerScale for Google Cloud enables customers to run their cloud workloads on the PowerScale scale-out NAS storage system. The following figure shows the architecture of PowerScale for Google Cloud. The three main parts are the Dell Technologies partner data center, the Dell Technologies Google Cloud organization (isiloncloud.com), and the customer’s Google Cloud organization (for example, customer-a.com and customer-b.com).

PowerScale for Google Cloud: a new release

We proudly released a new version of PowerScale for Google Cloud on July 8, 2022. It provides the following key features and enhancements:

More flexible configuration to choose

In the previous version of PowerScale for Google Cloud, only several pre-defined node tiers were available. With the latest version, you can purchase all PowerScale node types to fit your business needs and accelerate your native-cloud file service experience. 

New location available in EMEA region

In the previous version, the supported regions include North America and APJ (Australia and Singapore). We are now adding the EMEA region, which includes London, Frankfurt, Paris, and Warsaw.

Google Cloud VMware Engine (GCVE) Certification

PowerScale for Google Cloud is now certified to support GCVE. GCVE guest VMs can connect to PowerScale for Google Cloud file services to fully leverage PowerScale cluster storage. We’ll be taking a deeper look at the details in blog articles in the next few weeks.

Want to know more about the powerful cloud file service solution? Just click these links:

• PowerScale for Google Cloud Interactive Demo
• PowerScale for Google Cloud white paper
• PowerScale for Google Cloud User Documentation

Resources

• Google Cloud VMware Engine

Author: Lieven Lin

Quad-level cell (QLC) flash memory 15TB and 30TB drives have just been made available for the PowerScale F900 and F600 all-flash models. These new QLC drives, supported by the currently shipping OneFS 9.4 release, offer our customers optimum economics for NAS workloads that require performance, reliability, and capacity – such as financial modeling, media and entertainment, artificial intelligence (AI), machine learning (ML), and deep learning (DL). See the preview of this technology that we provided in May at Dell Technologies World (DTW).

PowerScale F900/F600 QLC raw capacity

QLC drives expand the data lake with up to 2x more capacity than previous generations in the same footprint, while delivering savings in consolidated rack space and power/cooling. From the edge to the core and to the cloud, PowerScale systems deliver simplicity, value, performance, flexibility, and choice.   

• Dell PowerScale with QLC drives delivers better efficiency with half the power and half the rack space required per TB as compared with current highest capacity node.¹
• Dell PowerScale with QLC drives delivers up to 2x higher raw cluster capacity as compared with current all-flash drives.²
• Dell PowerScale with QLC drives delivers up to 2x higher raw node density as compared with current all-flash drives.³
• Dell PowerScale with QLC drives delivers up to 19% lower price per TB as compared with current all-flash drives.⁴ 

PowerScale nodes comprised of QLC drives can deliver the same level of performance as those nodes comprised of TLC drives, while requiring only half the power and half the rack space. They are also up to 19% lower in price per TB, thus delivering superior economics and value to our customers. QLC-enabled nodes performed at parity or slightly better than TLC-enabled nodes for throughput benchmarks and SPEC workloads. ⁵

QLC drive-enabled nodes deliver the same performance as TLC while improving efficiency and doubling cluster capacity

These QLC drives become part of the overall lifecycle management system within OneFS which gives PowerScale a major TCO advantage over the competition. Seamless integration of nodes with QLC drives into existing PowerScale clusters allows clusters to take on new workloads. To address the storage capacity, performance needs, and cost optimization requirements for today’s workloads (while being powerful enough to handle the unpredictable demands of tomorrow), PowerScale systems are designed to provide customers choice, scale, and flexibility.

“With PowerScale, we have the flexibility to deploy the right storage with the right performance and right capacity to meet our business needs of today and the future,” said Michael Loggins, Global Vice President, Information Technology, SMC Corporation of America.

For more information about the PowerScale F600 and F900 QLC drives, visit the PowerScale all-flash spec sheet.

-------------------------------------------------------

¹Based on Dell internal analysis, June 2022. Actual results will vary.   

²Based on Dell internal analysis, June 2022.

³Based on Dell internal analysis, June 2022.

⁴Based on Dell internal pricing analysis, June 2022. Actual results will vary.   

⁵Based on Dell internal testing, April 2022. Actual results will vary. 

Author: Cris Banson

Recap

In the previous blog, we introduced the OneFS file permission basics, including:

1. OneFS file permission is only in one of the following states:

• POSIX mode bits - authoritative with a synthetic ACL
• OneFS ACL - authoritative with approximate POSIX mode bits

2. No matter the OneFS file permission state, the on-disk identity for a file is always a UID, a GID, or an SID. The name of a user or group is for display only.

3. When OneFS receives a user access request, it generates an access token for the user and compares the token to the file permissions based on UID/GID/SID.

Therefore, in this blog, we will explain what UID/GID/SID is, and will explain what a OneFS access token is. Now, let’s start by looking at UID/GID/SIDs.

UID/GID and SID

In our daily life, we are usually familiar with a username or a group name, which stands for a user or a group. In a NAS system, we use UID, GID, and SID to identify a user or a group, then the NAS system will resolve the UID, GID, and SID into a related username or group name.

The UID/GID is usually used in a UNIX environment to identify users/groups with a positive integer assigned. The UID/GID is usually provided by the local operating system and LDAP server.

The SID is usually used in a Windows environment to identify users/groups. The SID is usually provided by the local operating system and Active Directory (AD). The SID is written in the format:

            (SID)-(revision level)-(identifier-authority)-(subauthority1)-(subauthority2)-(etc)

for example:

S-1-5-21-1004336348-1177238915-682003330-512

For more information about SIDs, see the Microsoft article: What Are Security Identifiers?.

OneFS access token

In OneFS, information about users and groups is managed and stored in different authentication providers, including UID/GID and SID information, and user group membership information. OneFS can add multiple types of authentication provider, including:

• Active Directory (AD)
• Lightweight Directory Access Protocol (LDAP) servers
• NIS
• File provider
• Local provider

OneFS retrieves a user’s identity (UID/GID/SID) and group memberships from the above authentication providers. Assuming that we have a user named Joe, OneFS tries to resolve Joe’s UID/GID and group memberships from LDAP, NIS, file provider, and Local provider. Meanwhile, it also tries to resolve Joe’s SID and group memberships from AD, file provider, or local provider. 

• If neither UID/GID nor SID can be found in any of the authentication providers, the user does not exist. User access may be denied or be mapped to the ‘nobody’ user, depending on your protocol. 
• If only a UID/GID can be found or only a SID can be found, OneFS generates a fake UID or SID for the user.

It is not always the case that OneFS needs to resolve a user from username to UID/GID/SID. It is also possible that OneFS needs to resolve a user in reverse: that is, resolve a UID to its related username. This usually occurs when using NFSv3. When OneFS gets all UID/GID/SID information for a user, it will maintain the identity relationship in a local database, which records the UID <--> SID and GID <-->SID mapping, also known as the ID mapping function in OneFS.

Now, you should have an overall idea about how OneFS maintains the important UID/GID/SID information, and how to retrieve this information as needed.

Next, let’s see how OneFS can determine whether different usernames in different authentication types are actually the same real user. For example: how can we tell if the Joe in AD and the joe_f in LDAP is same guy or not? If they are the same, OneFS needs to ensure that they have the same access to the same file, even with different protocols.

That is the magic of the OneFS user mapping function. The default user mapping rule maps users together that have the same usernames in different authentication providers. For example, the Joe in AD and the Joe in LDAP will be considered the same user. You must create user mapping rules if a real user has different names in different authentication providers. The user mapping rule can have different operators, to provide more flexible management between different usernames in different authentication providers. The operators could be Append, Insert, Replace, Remove Groups, Join. See OneFS user mapping operators for more details. We just need to remember that the user mapping is just a function to determine if the user information in an authentication provider should be used when generating an access token. 

Although it is easy to confuse user mapping with ID mapping, user mapping is the process of identifying users across authentication providers for the purpose of token generation. After the token is generated, the mappings of SID<-->UID are placed in the ID mapping database.

Finally, OneFS must choose an authoritative identity (that is, an On-Disk Identity) from the collected/generated UID/GID/SID for the user, which will be stored on disk and is used when the file is created or when ownership of file changes, impacting the file permissions.

In a single protocol environment, determining the On-Disk Identity is simple because Windows uses SIDs and Linux uses UIDs. However, in a multi-protocol environment, only one identity is stored, and the challenge is determining which one is stored. By default, the policy configured for on-disk identity is Native mode. Native mode is the best option for most environments. OneFS selects the real value between the SID and UID/GID. If both the SID and UID/GID are real values, OneFS selects UID/GID. Please note that this blog series is based on the default policy setting.

Now you should have an overall understanding of user mapping, ID mapping, and on-disk identity. These are the key concepts when understanding user access tokens and doing troubleshooting. Finally, let’s see what an access token contains. 

You can view a user’s access token by using the command isi auth mapping token <username> in OneFS. Here is an example of Joe’s access token:

vonefs-aima-1# isi auth mapping token Joe
                   User
                       Name: Joe
                        UID: 2001
                        SID: S-1-5-21-1137111906-3057660394-507681705-1002
                    On Disk: 2001
                    ZID: 1
                   Zone: System
             Privileges: -
          Primary Group
                       Name: Market
                        GID: 2003
                        SID: S-1-5-21-1137111906-3057660394-507681705-1006
                    On Disk: 2003
Supplemental Identities
                       Name: Authenticated Users
                        SID: S-1-5-11 Below 

From the above output, we can see that an access token contains the following information:

• User’s username, UID, SID, and final on-disk identity
• Access zone ID and name
• OneFS RBAC privileges
• Primary group name, GID, SID, and final on-disk identity
• Supplemental group names, GID or SID.

Still, remember that we have a file created and owned by Joe in the previous blog? Here are the file permissions:

vonefs-aima-1# ls -le acl-file.txt
-rwxrwxr-x +   1 Joe  Market   69 May 28 01:08 acl-file.txt
 OWNER: user:Joe
 GROUP: group:Market
 0: user:Joe allow file_gen_all
 1: group:Market allow file_gen_read,file_gen_execute
 2: user:Bob allow file_gen_all
 3: everyone allow file_gen_read,file_gen_execute

The ls -le command here shows the user’s username only. And we already emphasized that the on-disk identity is always UID/GID or SID, so let’s use the ls -len command to show the on-disk identities. In the following output, we see that Joe’s on-disk identity is his UID 2001, and his GID 2003. When Joe wants to access the file, OneFS compares Joe’s access token with the file permissions below, finds that Joe’s UID is 2001 in his token, and grants him access to the file.

vonefs-aima-1# ls -len acl-file.txt
-rwxrwxr-x +   1 2001  2003   69 May 28 01:08 acl-file.txt
 OWNER: user:2001
 GROUP: group:2003
 0: user:2001 allow file_gen_all
 1: group:2003 allow file_gen_read,file_gen_execute
 2: user:2002 allow file_gen_all
 3: SID:S-1-1-0 allow file_gen_read,file_gen_execute

The above Joe is a OneFS local user from a local provider. Next, we will see what the access token looks like if a user’s SID is from AD and UID/GID is from LDAP.

Let’s assume that user John has an account named John_AD in AD, and also has an account named John_LDAP in LDAP server. This means that OneFS has to ensure that the two usernames have consistent access permissions on a file. To achieve that, we need to create a user mapping rule to join them together, so that the final access token will contain the SID information in AD and UID/GID information in LDAP. The access token for John_AD looks like this:

vonefs-aima-1# isi auth mapping token vlab\\John_AD
                   User
                       Name: VLAB\john_ad
                         UID: 1000019
                        SID: S-1-5-21-2529895029-2434557131-462378659-1110
                    On Disk: S-1-5-21-2529895029-2434557131-462378659-1110
                    ZID: 1
                   Zone: System
             Privileges: -
          Primary Group
                        Name: VLAB\domain users
                         GID: 1000041
                         SID: S-1-5-21-2529895029-2434557131-462378659-513
                    On Disk: S-1-5-21-2529895029-2434557131-462378659-513
Supplemental Identities
                        Name: Users
                         GID: 1545
                         SID: S-1-5-32-545
 
                        Name: Authenticated Users
                         SID: S-1-5-11
 
                       Name: John_LDAP
                        UID: 19421
                         SID: S-1-22-1-19421
 
                        Name: ldap_users
                         GID: 32084
                         SID: S-1-22-2-32084

Assume that a file that is owned and only accessible by John_LDAP has the file permissions shown in the following output. As the John_AD and John_LDAP is joined together with a user mapping rule, the John_LDAP identity (UID) is also in the John_AD access token, so John_AD can also access the file.

vonefs-aima-1# ls -le john_ldap.txt
-rwx------     1 John_LDAP  ldap_users  19 Jun 15 07:36 john_ldap.txt
 OWNER: user:John_LDAP
 GROUP: group:ldap_users
 SYNTHETIC ACL
 0: user:John_LDAP allow file_gen_read,file_gen_write,file_gen_execute,std_write_dac
 1: group:ldap_users allow std_read_dac,std_synchronize,file_read_attr

You should now have an understanding of OneFS access tokens, and how they are used to determine a user’s authorized operation on data, through file permission checking.

In my next blog, we will see what will happen for different protocols when accessing OneFS data.

Resources

• ID mapping
• user mapping
• OneFS user mapping operators
• on-disk identity

Author: Lieven Lin

OneFS protects data stored on failing nodes or drives in a cluster through a process called smartfail. During the process, OneFS places a device into quarantine and, depending on the severity of the issue, the data on it into a read-only state. While a device is quarantined, OneFS reprotects the data on the device by distributing the data to other devices.

After all data eviction or reconstruction is complete, OneFS logically removes the device from the cluster, and the node or drive can be physically replaced. OneFS only automatically smartfails devices as a last resort. Nodes and/or drives can also be manually smartfailed. However, it is strongly recommended to first consult Dell Technical Support.

Occasionally a device might fail before OneFS detects a problem. If a drive fails without being smartfailed, OneFS automatically starts rebuilding the data to available free space on the cluster. However, because a node might recover from a transient issue, if a node fails, OneFS does not start rebuilding data unless it is logically removed from the cluster.

A node that is unavailable and reported by isi status as ‘D’, or down, can be smartfailed. If the node is hard down, likely with a significant hardware issue, the smartfail process will take longer because data has to be recalculated from the FEC protection parity blocks. That said, it’s well worth attempting to bring the node up if at all possible – especially if the cluster, and/or node pools, is at the default +2D:1N protection. The concern here is that, with a node down, there is a risk of data loss if a drive or other component goes bad during the smartfail process.

If possible, and assuming the disk content is still intact, it can often be quicker to have the node hardware repaired. In this case, the entire node’s chassis (or compute module in the case of Gen 6 hardware) could be replaced and the old disks inserted with original content on them. This should only be performed at the recommendation and under the supervision of Dell Technical Support. If the node is down because of a journal inconsistency, it will have to be smartfailed out. In this case, engage Dell Technical Support to determine an appropriate action plan.

The recommended procedure for smartfailing a node is as follows. In this example, we’ll assume that node 4 is down:

From the CLI of any node except node 4, run the following command to smartfail out the node:

# isi devices node smartfail --node-lnn 4

Verify that the node is removed from the cluster.

# isi status –q

(An ‘—S-’ will appear in node 4’s ‘Health’ column to indicate it has been smartfailed).

Monitor the successful completion of the job engine’s MultiScan, FlexProtect/FlexProtectLIN jobs:

# isi job status

Un-cable and remove the node from the rack for disposal.

As mentioned previously, there are two primary Job Engine jobs that run as a result of a smartfail:

• MultiScan
• FlexProtect or FlexProtectLIN

MultiScan performs the work of both the AutoBalance and Collect jobs simultaneously, and it is triggered after every group change. The reason is that new file layouts and file deletions that happen during a disruption to the cluster might be imperfectly balanced or, in the case of deletions, simply lost.

The Collect job reclaims free space from previously unavailable nodes or drives. A mark and sweep garbage collector, it identifies everything valid on the filesystem in the first phase. In the second phase, the Collect job scans the drives, freeing anything that isn’t marked valid.

When node and drive usage across the cluster are out of balance, the AutoBalance job scans through all the drives looking for files to re-layout, to make use of the less filled devices.

The purpose of the FlexProtect job is to scan the file system after a device failure to ensure that all files remain protected. Incomplete protection levels are fixed, in addition to missing data or parity blocks caused by drive or node failures. This job is started automatically after smartfailing a drive or node. If a smartfailed device was the reason the job started, the device is marked gone (completely removed from the cluster) at the end of the job.

Although a new node can be added to a cluster at any time, it’s best to avoid major group changes during a smartfail operation. This helps to avoid any unnecessary interruptions of a critical job engine data reprotection job. However, because a node is down, there is a window of risk while the cluster is rebuilding the data from that cluster. Under pressing circumstances, the smartfail operation can be paused, the node added, and then smartfail resumed when the new node has happily joined the cluster.

Be aware that if the node you are adding is the same node that was smartfailed, the cluster maintains a record of that node and may prevent the re-introduction of that node until the smartfail is complete. To mitigate risk, Dell Technical Support should definitely be involved to ensure data integrity.

The time for a smartfail to complete is hard to predict with any accuracy, and depends on:

Typical smartfail runtimes range from minutes (for fairly empty, idle nodes with SSD and SAS drives) to days (for nodes with large SATA drives and a high capacity utilization). The FlexProtect job already runs at the highest job engine priority (value=1) and medium impact by default. As such, there isn’t much that can be done to speed up this job, beyond reducing cluster load.

Smartfail is also a valuable tool for proactive cluster node replacement, such as during a hardware refresh. Provided that the cluster quorum is not broken, a smartfail can be initiated on multiple nodes concurrently – but never more than n/2 – 1 nodes (rounded up)!

If replacing an entire node pool as part of a tech refresh, a SmartPools filepool policy can be crafted to migrate the data to another node pool across the backend network. When complete, the nodes can then be smartfailed out, which should progress swiftly because they are now empty.

If multiple nodes are smartfailed simultaneously, at the final stage of the process the node remove is serialized with roughly a 60 second pause between each. The smartfail job places the selected nodes in read-only mode while it copies the protection stripes to the cluster’s free space. Using SmartPools to evacuate data from a node or set of nodes, in preparation to remove them, is generally a good idea, and usually a relatively fast process.

SmartPools’ Virtual Hot Spare (VHS) functionality helps ensure that node pools maintain enough free space to successfully re-protect data in the event of a smartfail. Though configured globally, VHS actually operates at the node pool level so that nodes with different size drives reserve the appropriate VHS space. This helps ensure that while data may move from one disk pool to another during repair, it remains on the same class of storage. VHS reservations are cluster wide and configurable, as either a percentage of total storage (0-20%), or as a number of virtual drives (1-4), with the default being 10%.

Note: a smartfail is not guaranteed to remove all data on a node. Any pool in a cluster that’s flagged with the ‘System’ flag can store /ifs/.ifsvar data. A filepool policy to move the regular data won’t address this data. Also, because SmartPools ‘spillover’ may have occurred at some point, there is no guarantee that an ‘empty’ node is completely devoid of data. For this reason, OneFS still has to search the tree for files that may have blocks residing on the node.

Nodes can be easily smartfailed from the OneFS WebUI by navigating to Cluster Management > Hardware Configuration and selecting ‘Actions > More > Smartfail Node’ for the desired node(s):

Similarly, the following CLI commands first initiate and then halt the node smartfail process, respectively. First, the ‘isi devices node smartfail’ command kicks off the smartfail process on a node and removes it from the cluster.

# isi devices node smartfail -h
Syntax
# isi devices node smartfail
[--node-lnn <integer>]
[--force | -f]
[--verbose | -v]

If necessary, the ‘isi devices node stopfail’ command can be used to discontinue the smartfail process on a node.

# isi devices node stopfail -h
Syntax
isi devices node stopfail
[--node-lnn <integer>]
[--force | -f]
[--verbose | -v]

Similarly, individual drives within a node can be smartfailed with the ‘isi devices drive smartfail’ CLI command.

# isi devices drive smartfail { <bay> | --lnum <integer> | --sled <string> }
        [--node-lnn <integer>]
        [{--force | -f}]
        [{--verbose | -v}]
        [{--help | -h}]

Author: Nick Trimbee

Traditionally, OneFS has used the SmartPools jobs to apply its file pool policies. To accomplish this, the SmartPools job visits every file, and the SmartPoolsTree job visits a tree of files. However, the scanning portion of these jobs can result in significant random impact to the cluster and lengthy execution times, particularly in the case of the SmartPools job. To address this, OneFS also provides the FilePolicy job, which offers a faster, lower impact method for applying file pool policies than the full-blown SmartPools job.

But first, a quick Job Engine refresher…

As we know, the Job Engine is OneFS’ parallel task scheduling framework, and is responsible for the distribution, execution, and impact management of critical jobs and operations across the entire cluster.

The OneFS Job Engine schedules and manages all data protection and background cluster tasks: creating jobs for each task, prioritizing them, and ensuring that inter-node communication and cluster wide capacity utilization and performance are balanced and optimized. Job Engine ensures that core cluster functions have priority over less important work and gives applications integrated with OneFS – Isilon add-on software or applications integrating to OneFS by means of the OneFS API – the ability to control the priority of their various functions to ensure the best resource utilization.

Each job, such as the SmartPools job, has an “Impact Profile” comprising a configurable policy and a schedule that characterizes how much of the system’s resources the job will take – plus an Impact Policy and an Impact Schedule. The amount of work a job has to do is fixed, but the resources dedicated to that work can be tuned to minimize the impact to other cluster functions, like serving client data.

Here’s a list of the specific jobs that are directly associated with OneFS SmartPools:

In conjunction with the IndexUpdate job, FilePolicy improves job scan performance by using a ‘file system index’, or changelist, to find files needing policy changes, rather than a full tree scan.

Avoiding a full treewalk dramatically decreases the amount of locking and metadata scanning work the job is required to perform, reducing impact on CPU and disk – albeit at the expense of not doing everything that SmartPools does. The FilePolicy job enforces just the SmartPools file pool policies, as opposed to the storage pool settings. For example, FilePolicy does not deal with changes to storage pools or storage pool settings, such as:

• Restriping activity due to adding, removing, or reorganizing node pools
• Changes to storage pool settings or defaults, including protection

However, most of the time, SmartPools and FilePolicy perform the same work. Disabled by default, FilePolicy supports the full range of file pool policy features, reports the same information, and provides the same configuration options as the SmartPools job. Because FilePolicy is a changelist-based job, it performs best when run frequently – once or multiple times a day, depending on the configured file pool policies, data size, and rate of change.

Job schedules can easily be configured from the OneFS WebUI by navigating to Cluster Management > Job Operations, highlighting the desired job, and selecting ‘View\Edit’. The following example illustrates configuring the IndexUpdate job to run every six hours at a LOW impact level with a priority value of 5:

When enabling and using the FilePolicy and IndexUpdate jobs, the recommendation is to continue running the SmartPools job as well, but at a reduced frequency (monthly).

In addition to running on a configured schedule, the FilePolicy job can also be executed manually.

FilePolicy requires access to a current index. If the IndexUpdate job has not yet been run, attempting to start the FilePolicy job will fail with the error shown in the following figure. Instructions in the error message appear, prompting to run the IndexUpdate job first. When the index has been created, the FilePolicy job will run successfully. The IndexUpdate job can be run several times daily (that is, every six hours) to keep the index current and prevent the snapshots from getting large.

Consider using the FilePolicy job with the job schedules below for workflows and datasets with the following characteristics:

• Data with long retention times
• Large number of small files
• Path-based File Pool filters configured
• Where the FSAnalyze job is already running on the cluster (InsightIQ monitored clusters)
• There is already a SnapshotIQ schedule configured
• When the SmartPools job typically takes a day or more to run to completion at LOW impact

For clusters without the characteristics described above, the recommendation is to continue running the SmartPools job as usual and not to activate the FilePolicy job.

The following table provides a suggested job schedule when deploying FilePolicy:

Because no two clusters are the same, this suggested job schedule may require additional tuning to meet the needs of a specific environment.

Note that when clusters running older OneFS versions and the FSAnalyze job are upgraded to OneFS 8.2.x or later, the legacy FSAnalyze index and snapshots are removed and replaced by new snapshots the first time that IndexUpdate is run. The new index stores considerably more file and snapshot attributes than the old FSA index. Until the IndexUpdate job effects this change, FSA keeps running on the old index and snapshots.

Author: Nick Trimbee

Introduction

CloudPools 2.0 brings many improvements and is released along with OneFS 8.2.0. It’s valuable to be able to upgrade OneFS from 8.x to 8.2.x or later and leverage the data management benefits of CloudPools 2.0.

This blog describes the preparations for upgrading a CloudPools environment. The purpose is to avoid potential issues when upgrading OneFS from 8.x to 8.2.x or later (that is, from CloudPools 1.0 to CloudPools 2.0).

For the recommended procedure for upgrading a CloudPools environment, see the document PowerScale CloudPools: Upgrading 8.x to 8.2.2.x or later.

For the best practices and considerations for CloudPools upgrades, see the white paper Dell PowerScale: CloudPools and ECS.

This blog covers the preparations both on cloud providers and on PowerScale clusters.

Cloud providers

CloudPools is a OneFS feature that allows customers to archive or tier data from a PowerScale cluster to cloud storage, including public cloud providers such as Amazon Web Services (AWS), Microsoft Azure, Google Cloud, Alibaba Cloud, or a private cloud based on Dell ECS.

Important: Run the isi cloud account list command to verify which cloud providers are used for CloudPools. Different authentications are used with different cloud providers for CloudPools, which might cause potential issues when upgrading a CloudPools environment.

AWS signature authentication is used for AWS, Dell ECS, and Google Cloud. In OneFS releases prior to 8.2, AWS SigV2 is only supported for CloudPools. Starting from OneFS 8.2, AWS SigV4 is added, which provides an extra level of security for authentication with the enhanced algorithm. For more information about V4, see Authenticating Requests: AWS Signature V4. AWS SigV4 will be used automatically for CloudPools in OneFS 8.2.x or later if the configurations (CloudPools and cloud providers) are correct. Please note that a different authentication is used for Azure or Alibaba Cloud.

If public cloud providers are used in a customer’s environment, there should be no issues because all configurations are already created by public cloud providers.

If Dell ECS is used in a customer’s environment, the ECS configurations are implemented separately and you need make sure that the configurations are correct on ECS, including load balancer and Domain Name System (DNS).

This section only covers the preparations for CloudPools and Dell ECS before upgrading OneFS from 8.x to 8.2.x or later.

Dell ECS

In general, CloudPools may already be archiving a lot of data from a PowerScale (Isilon) cluster to ECS before an upgrade OneFS from 8.x to 8.2.x or later. That means that most of the configurations should be created for CloudPools. For more information about CloudPools and ECS, see the white paper Dell PowerScale: CloudPools and ECS.

This section covers the following configurations for ECS before a OneFS upgrade from 8.x to 8.2.x or later.

• Load balancer
• DNS
• Base URL

Load balancer

A load balancer balances traffic to the various ECS nodes from the PowerScale cluster, and can provide much better performance and throughput for CloudPools. A load balancer is strongly recommended for CloudPools 2.0 and ECS. The following white papers provide information about how to implement a load balancer with ECS:

• ECS with HAProxy
• ECS with NGINX (OpenResty)
• ECS with F5
• ECS with Kemp LoadMaster

DNS

AWS always has a wildcard DNS record configured. See the document Virtual hosting of buckets, which introduces path-style access and virtual hosted-style access for a bucket. It also shows how to associate a hostname with an Amazon S3 bucket using CNAMEs for virtual hosted-style access.

Meanwhile, the path-style URL will be deprecated on September 23, 2022. Buckets created after that date must be referenced using the virtual-hosted model. For the reasons behind moving to the virtual-hosted model, see the document Amazon S3 Path Deprecation Plan – The Rest of the Story.

ECS supports Amazon S3 compatible applications that use virtual host-style and path-style addressing schemes. (For more information, see document Bucket and namespace addressing.) And, to help ensure the proper DNS configuration for ECS, see the document DNS configuration.

The procedure for configuring DNS depends on your DNS server or DNS provider.

For example, a DNS is set up on a Windows server. The following two tables and three figures show the DNS entries created. The customer must create their own DNS entries.

Base URL

In CloudPools 2.0 and ECS, a base URL must be created on ECS. For details about creating a Base URL on ECS, see the section Appendix A Base URL in the white paper Dell PowerScale: CloudPools and ECS.

When creating a new Base URL, keep the default setting (No) for Use with Namespace. Make sure that the Base URL is the FQDN alias of the load balancer virtual IP.

PowerScale clusters

If SyncIQ is configured for CloudPools, run the following commands on the source and target PowerScale cluster to check and record the CloudPools configurations, including CloudPools storage accounts, CloudPool, file pool policies, and SyncIQ policies.

# isi cloud accounts list -v
# isi cloud pools list -v
# isi filepool policies list -v
# isi sync policies list -v

For CloudPools and ECS, please be sure that URI is the FQDN alias of the load balancer virtual IP.

Important: It is strongly recommended that no job (such as for CloudPools/SmartPools, SyncIQ, and NDMP) be running before upgrading.  

In a SyncIQ environment, upgrade the SyncIQ target cluster before upgrading the source cluster. OneFS allows SyncIQ to send CP1.0 formatted SmartLink files to the target, where they will be converted into CP2.0 formatted SmartLink files. (If the source cluster is upgraded first, Sync operations will fail until both are upgraded; the only known resolution is to reconfigure the Sync policy to "Deep Copy".)

And the customer may have active (read & write) CloudPools accounts both on source and target PowerScale clusters, replicating SmartLink files of active CloudPools accounts bidirectionally. That means that the source is also a target. In this case, you need to reconfigure the Sync policy to “Deep Copy” on one of PowerScale clusters. After that, the target with replicated SmartLink files should be upgraded first.

Summary

This blog covered what you need to check, on cloud providers and PowerScale clusters, before upgrading OneFS from 8.x to 8.2.x or later (that is, from CloudPools 1.0 to CloudPools 2.0). My hope is that it can help you avoid potential CloudPools issues when upgrading a CloudPools environment.

Author: Jason He, Principal Engineering Technologist

Dell PowerScale OneFS 9.3.0.0 first introduced support for Secure Boot on the Dell Isilon A2000 platform. Now, OneFS 9.4.0.0 expands that support across the PowerScale A300, A3000, B100, F200, F600, F900, H700, H7000, and P100 platforms.

Secure Boot was introduced as part of the Unified Extensible Firmware Interface (UEFI) Forums of the UEFI 2.3.1 specification. The goal for Secure Boot is to ensure device security in the preboot environment by allowing only authorized EFI binaries to be loaded during the process.

The operating system boot loaders are signed with a digital signature. PowerScale Secure Boot takes the UEFI framework further by including the OneFS kernel and modules. The UEFI infrastructure is responsible for the EFI signature validation and binary loading within UEFI Secure Boot. Also, the FreeBSD veriexec function can perform signature validation for the boot loader and kernel. The PowerScale Secure Boot feature runs during the nodes’ bootup process only, using public-key cryptography to verify the signed code and ensure that only trusted code is loaded on the node.

Supported platforms

PowerScale Secure Boot is available on the following platform:

Considerations

Before configuring the PowerScale Secure Boot feature, consider the following:

• Isilon and PowerScale nodes are not shipped with PowerScale Secure Boot enabled. However, you can enable the feature to meet site requirements.
• A PowerScale cluster composed of PowerScale Secure Boot enabled nodes, and PowerScale Secure Boot disabled nodes, is supported.
• A license is not required for PowerScale Secure Boot because the feature is natively supported.
• At any point, you can enable or disable the PowerScale Secure Boot feature.
• Plan a maintenance window to enable or disable the PowerScale Secure Boot feature, because a node reboot is required during the process to toggle the feature.
• The PowerScale Secure Boot feature does not impact cluster performance, because the feature is only run at bootup.

Configuration

For more information about configuring the PowerScale Secure Boot feature, see the document Dell PowerScale OneFS Secure Boot.

Author: Aqib Kazi

There have been a couple of recent inquiries from the field about the SnapRevert job.

For context, SnapRevert is one of three main methods for restoring data from a OneFS snapshot. The options are shown here: 

However, the most efficient of these approaches is the SnapRevert job, which automates the restoration of an entire snapshot to its top-level directory. This allows for quickly reverting to a previous, known-good recovery point (for example, if there is a virus outbreak). The SnapRevert job can be run from the Job Engine WebUI, and requires adding the desired snapshot ID.

There are two main components to SnapRevert:

• The file system domain that the objects are put into.
• The job that reverts everything back to what’s in a snapshot.

So, what exactly is a SnapRevert domain? At a high level, a domain defines a set of behaviors for a collection of files under a specified directory tree. The SnapRevert domain is described as a restricted writer domain, in OneFS parlance. Essentially, this is a piece of extra filesystem metadata and associated locking that prevents a domain’s files from being written to while restoring a last known good snapshot.

Because the SnapRevert domain is essentially just a metadata attribute placed onto a file/directory, a best practice is to create the domain before there is data. This avoids having to wait for DomainMark (the aptly named job that marks a domain’s files) to walk the entire tree, setting that attribute on every file and directory within it.

The SnapRevert job itself actually uses a local SyncIQ policy to copy data out of the snapshot, discarding any changes to the original directory. When the SnapRevert job completes, the original data is left in the directory tree. In other words, after the job completes, the file system (HEAD) is exactly as it was at the point in time that the snapshot was taken. The LINs for the files or directories do not change because what is there is not a copy.

To manually run SnapRevert, go to the OneFS WebUI > Cluster Management > Job Operations > Job Types > SnapRevert, and click the Start Job button.

Also, you can adjust the job’s impact policy and relative priority, if desired.

Before a snapshot is reverted, SnapshotIQ creates a point-in-time copy of the data that is being replaced. This enables the snapshot revert to be undone later, if necessary.

Also, individual files, rather than entire snapshots, can also be restored in place using the isi_file_revert command-line utility.

# isi_file_revert
usage:
isi_file_revert -l lin -s snapid
isi_file_revert -p path -s snapid
-d (debug output)
-f (force, no confirmation)

This can help drastically simplify virtual machine management and recovery, for example.

Before creating snapshots, it is worth considering that reverting a snapshot requires that a SnapRevert domain exist for the directory that is being restored. As such, we recommend that you create SnapRevert domains for those directories while the directories are empty. Creating a domain for an empty (or sparsely populated) directory takes considerably less time.

Files may belong to multiple domains. Each file stores a set of domain IDs indicating which domain they belong to in their inode’s extended attributes table. Files inherit this set of domain IDs from their parent directories when they are created or moved. The domain IDs refer to domain settings themselves, which are stored in a separate system B-tree. These B-tree entries describe the type of the domain (flags), and various other attributes.

As mentioned, a Restricted-Write domain prevents writes to any files except by threads that are granted permission to do so. A SnapRevert domain that does not currently enforce Restricted-Write shows up as (Writable) in the CLI domain listing.

Occasionally, a domain will be marked as (Incomplete). This means that the domain will not enforce its specified behavior. Domains created by the job engine are incomplete if not all files that are part of the domain are marked as being members of that domain. Since each file contains a list of domains of which it is a member, that list must be kept up to date for each file. The domain is incomplete until each file’s domain list is correct.

Besides SnapRevert, OneFS also uses domains for SyncIQ replication and SnapLock immutable archiving.

A SnapRevert domain must be created on a directory before it can be reverted to a particular point in time snapshot. As mentioned before, we recommend creating SnapRevert domains for a directory while the directory is empty.

The root path of the SnapRevert domain must be the same root path of the snapshot. For instance, a domain with a root path of /ifs/data/marketing cannot be used to revert a snapshot with a root path of /ifs/data/marketing/archive.

For example, for snapshot DailyBackup_04-27-2021_12:00 which is rooted at /ifs/data/marketing/archive, you would perform the following:

1. Set the SnapRevert domain by running the DomainMark job (which marks all files).

# isi job jobs start domainmark --root /ifs/data/marketing --dm-type SnapRevert

2. Verify that the domain has been created.

# isi_classic domain list –l

To restore a directory back to the state it was in at the point in time when a snapshot was taken, you need to:

• Create a SnapRevert domain for the directory
• Create a snapshot of a directory

 To accomplish this, do the following:

1. Identify the ID of the snapshot you want to revert by running the isi snapshot snapshots view command and picking your point in time (PIT).

For example:

# isi snapshot snapshots view DailyBackup_04-27-2021_12:00
ID: 38
Name: DailyBackup_04-27-2021_12:00
Path: /ifs/data/marketing
Has Locks: No
Schedule: daily
Alias: -
Created: 2021-04-27T12:00:05
Expires: 2021-08-26T12:00:00
Size: 0b
Shadow Bytes: 0b
% Reserve: 0.00%
% Filesystem: 0.00%
State: active

2. Revert to a snapshot by running the isi job jobs start command. The following command reverts to snapshot ID 38 named DailyBackup_04-27-2021_12:00.

# isi job jobs start snaprevert --snapid 38

You can also perform this action from the WebUI. Go to Cluster Management > Job Operations > Job Types > SnapRevert, and click the Start Job button.

OneFS automatically creates a snapshot before the SnapRevert process reverts the specified directory tree. The naming convention for these snapshots is of the form: <snapshot_name>.pre_revert.*

# isi snap snap list | grep pre_revert
39 DailyBackup_04-27-2021_12:00.pre_revert.1655328160 /ifs/data/marketing

This allows for an easy rollback of a SnapRevert if the desired results are not achieved.

If a domain is currently preventing the modification or deletion of a file, a protection domain cannot be created on a directory that contains that file. For example, if files under /ifs/data/smartlock are set to a WORM state by a SmartLock domain, OneFS will not allow a SnapRevert domain to be created on /ifs/data/.

If desired or required, SnapRevert domains can also be deleted using the job engine CLI. For example, to delete the SnapRevert domain at /ifs/data/marketing:

# isi job jobs start domainmark --root /ifs/data/marketing --dm-type SnapRevert --delete

Author: Nick Trimbee

About this blog series

Have you ever been confused about PowerScale OneFS file system multi-protocol data access? If so, this blog series will help you out. We’ll try to demystify OneFS multi-protocol data access. Different Network Attached Storage vendors have different designs for implementing multi-protocol data access. In OneFS multi-protocol data access, you can access the same set of data consistently with different operating systems and protocols.

To make it simple, the overall data access process in OneFS includes:

1. When a client user tries to access OneFS cluster data by means of protocols (such as SMB, NFS, and S3), OneFS must first authenticate the client user.
2. When the authentication succeeds, OneFS checks whether the user has permission on file share, where the access level depends on your access protocol, such as SMB share, NFS export, or S3 bucket.
3. Only when the user is authorized to have permission on the file shares will OneFS apply user mapping rules and generate an access token for the user in most cases. The access token contains the following information:

• The user's Security Identifier (SID), User Identifier (UID), and Group Identifier (GID).
• The user's supplemental groups
• The user's role-based access control (RBAC) privileges

Finally, OneFS enforces the permissions on the target data for the user. This process evaluates the file permissions based on the user's access token and file share level permissions.

Does it sound simple but some details still confusing? Like, what exactly are UIDs, GIDs, and SIDs? What’s an access token? How does OneFS evaluate the file permissions? and so on. Don’t worry if you are not familiar with these concepts. Keep reading and we’ll explain!

To make it easier, we will start with OneFS file permissions, and then introduce OneFS access tokens. Finally, we will see how data access depends on the protocol you use.

In this blog series, we’ll cover the following topics:

• Data Access in OneFS - Part 1: Introduction to OneFS File Permissions
• Data Access in OneFS - Part 2: Introduction to OneFS Access Tokens
• Data Access in OneFS - Part 3: Why Use Different Protocols?
• Data Access in OneFS - Part 4: Using NFSv3 and NFSv4.x
• Data Access in OneFS - Part 5: Using SMB
• Data Access in OneFS - Part 6: Using S3
• More to add…

Now let's have a look at OneFS file permissions. In a multi-protocol environment, the OneFS operating system is designed to support basic POSIX mode bits and Access Control Lists (ACLs). Therefore, two file permission states are designated:

• POSIX mode bits - authoritative with a synthetic ACL
• OneFS ACL - authoritative with approximate POSIX mode bits

POSIX mode bits - authoritative with a synthetic ACL

POSIX mode bits only define three specific permissions: read(r), write(w), and execute(x). Meanwhile, there are three classes to which you can assign permissions: Owner, Group, and Others.

• Owner: represents the owner of a file/directory.
• Group: represents the group of a file/directory.
• Others: represents the users who are not the owner, nor a member of the group.

The ls -le command displays a file’s permissions; the ls -led command displays a directory’s permissions. If it has these permissions:

-rw-rw-r--

then:

-rw-rw-r--         means that the owner has read and write permissions 

-rw-rw-r--         means that the group has read and write permissions

-rw-rw-r--         means that all others have only read permissions

In the following example for the file posix-file.txt, the file owner Joe has read and write access permissions, the file group Market has read and write access permissions, and all others only have read access permissions.

Also displayed here is the synthetic ACL (shown beneath the SYNTHETIC ACL flag) which indicates that the file is in the POSIX mode bit file permission state. There are three Access Control Entities (ACEs) created for the synthetic ACL, all of which is another way of representing the file’s POSIX mode bits permissions.

vonefs-aima-1# ls -le posix-file.txt
-rw-rw-r--     1 Joe  Market   65 May 28 02:08 posix-file.txt
 OWNER: user:Joe
 GROUP: group:Market
 SYNTHETIC ACL
 0: user:Joe allow file_gen_read,file_gen_write,std_write_dac
 1: group:Market allow file_gen_read,file_gen_write
 2: everyone allow file_gen_read

When OneFS receives a user access request, it generates an access token for the user and compares the token to the file permissions – in this case, the POSIX mode bits.  

OneFS ACL authoritative with approximate POSIX mode bits

In contrast to POSIX mode bits, OneFS ACLs support more expressive permissions. (For all available permissions, which are listed in Table 1 through Table 3 of the documentation, see Access Control Lists on Dell EMC PowerScale OneFS.) A OneFS ACL consists of one or more Access Control Entries (ACEs). A OneFS ACE contains the following information:

• ACE index: indicates the ACE order in an ACL
• Identity type: indicates the identity type, supported identity type including user, group, everyone, creator_owner, creator_group, or owner_rights
• Identity ID: in OneFS, the UID/GID/SID is stored on disk instead of user names or group names. The name of a user or group is for display only.
• ACE type: The type of the ACE (allow or deny)
• ACE permissions and inheritance flags: A list of permissions and inheritance flags separated by commas

For example, the ACE "0: group:Engineer allow file_gen_read,file_gen_execute" indicates that its index is 0, and allows the group called Engineer to have file_gen_read and file_gen_execute access permissions.

The following example shows a full ACL for a file. Although there is no SYNTHETIC ACL flag, there is a "+" character following the POSIX mode bits that indicates that the file is in the OneFS real ACL state. The file’s OneFS ACL grants full permission to users Joe and Bob. It also grants file_gen_read and file_gen_execute permissions to the group Market and to everyone. In this case, the POSIX mode bits are for representation only: you cannot tell the accurate file permissions from the approximate POSIX mode bits. You should therefore always rely on the OneFS ACL to check file permissions.

vonefs-aima-1# ls -le acl-file.txt
-rwxrwxr-x +   1 Joe  Market   69 May 28 01:08 acl-file.txt
 OWNER: user:Joe
 GROUP: group:Market
 0: user:Joe allow file_gen_all
 1: group:Market allow file_gen_read,file_gen_execute
 2: user:Bob allow file_gen_all
 3: everyone allow file_gen_read,file_gen_execute

No matter the OneFS file permission state, the on-disk identity for a file is always a UID, a GID, or an SID. So, for the above two files, file permissions stored on disk are:

vonefs-aima-1# ls -len posix-file.txt
-rw-rw-r--     1 2001  2003   65 May 28 02:08 posix-file.txt
 OWNER: user:2001
 GROUP: group:2003
 SYNTHETIC ACL
 0: user:2001 allow file_gen_read,file_gen_write,std_write_dac
 1: group:2003 allow file_gen_read,file_gen_write
 2: SID:S-1-1-0 allow file_gen_read
 
vonefs-aima-1# ls -len acl-file.txt
-rwxrwxr-x +   1 2001  2003   69 May 28 01:08 acl-file.txt
 OWNER: user:2001
 GROUP: group:2003
 0: user:2001 allow file_gen_all
 1: group:2003 allow file_gen_read,file_gen_execute
 2: user:2002 allow file_gen_all
 3: SID:S-1-1-0 allow file_gen_read,file_gen_execute

When OneFS receives a user access request, it generates an access token for the user and compares the token to the file permissions. OneFS grants access when the file permissions include an ACE that allows the identity in the token to access the file, and does not include an ACE that denies the identity access.

When evaluating the file permission for a user's access token, OneFS checks the ACEs one by one by following the ACEs index order and stops checking when the following conditions are met:

• All of the required permissions for the user access request are allowed by ACLs, and the access request is authorized.
• Any one of the required permissions for the user access request is explicitly denied by ACLs, and the access request is denied.
• All ACEs have been checked, but not all required permissions for the user access request are allowed by ACLs, then the access request is also denied.

Let’s say we have a file named acl-file01.txt that has the file permissions shown below. When user Bob tries to read the data of the file, OneFS checks the ACEs from index 0 to index 3. When checking ACE index 1, it explicitly denies Bob read data permissions. The ACLs then stop checking, and read access is denied.

vonefs-aima-1# ls -le acl-file01.txt
-rwxrw-r-- +   1 Joe  Market   12 May 28 06:19 acl-file01.txt
 OWNER: user:Joe
 GROUP: group:Market
 0: user:Joe allow file_gen_all
 1: user:Bob deny file_gen_read
 2: user:Bob allow file_gen_read,file_gen_write
 3: everyone allow file_gen_read

Now let’s say that we still have the file named acl-file01.txt, but the file permissions are now a little different, as shown below. When user Bob tries to read the data of the file, OneFS checks the ACEs from index 0 to index 3. When checking ACE index 1, it explicitly allows Bob to have read permissions. The ACLs checking process therefore ends, and read access is authorized. Therefore, it is recommended to put all “deny” ACEs in front of “allow” ACEs if you want to explicitly deny specific permissions for specific users/groups.

vonefs-aima-1# ls -le acl-file01.txt
-rwxrw-r-- +   1 Joe  Market   12 May 28 06:19 acl-file01.txt
 OWNER: user:Joe
 GROUP: group:Market
 0: user:Joe allow file_gen_all
 1: user:Bob allow file_gen_read,file_gen_write
 2: user:Bob deny file_gen_read
 3: everyone allow file_gen_read

File permission state changes

As mentioned before, a file can only be in one state at a time. However, the file permission state of the file may be flipped. If a file is in POSIX, it can be flipped to an ACL file by modifying the permissions using SMB/NFSv4 clients or by using the chmod command in OneFS. If a file is in ACL, it can be flipped to a POSIX file, by using the OneFS CLI command: chmod –b XXX <filename>. The ‘XXX’ specifies the new POSIX permission. For more examples, see File permission state changes.

Now, you should be able to check a file’s permission on OneFS with the command ls -len filename, and check a directory’s permissions on OneFS with the command ls -lend directory_name.

In my next blog, we will cover what an access token is and how to check a user’s access token!

Resources

• Access Control Lists on Dell PowerScale OneFS
• File permission state changes

Author: Lieven Lin

Recently a customer contacted us to tell us that he thought that there was an error in the output of the OneFS CLI command ‘isi_cstats’. Starting with OneFS 9.3, the ‘isi_cstats’ command includes the accounted number of inlined files within /ifs. It also contains a statistic called “Total inlined data savings”.

This customer expected that the ‘Total inlined data savings’ number was simply ‘Total inlined files’ multiplied by 8KB. The reason he thought this number was wrong was that this number does not consider the protection level. 

In OneFS, for the 2d:1n protection level, each file smaller than 128KB is stored as 3X mirrors. Take the screenshot below as an example.

If we do some calculation here,

379,948,336 * 8KB = 3,039,586,688KiB = 2898.78GiB

we can see that the 2,899GiB from the command output is calculated as one block per inlined file. So, in our example, the customer would think that ‘Total inlined data savings’ should report 2898.78 GiB * 3, because of the 2d:1n protection level. 

Well, this statistic is not the actual savings, it is really the logical on-disk cost for all inlined files. We can't accurately report the physical savings because it depends on the non-inlined protection overhead, which can vary. For example:

• If the protection level is 2d:1n, without the data inlining in 8KB inode feature, each of the inlined files would cost 8KB * 3.
• If the protection level is 3d:1n1d, it will become 8KB * 4.

One more thing to consider, if a file is smaller than 8KB after compression, it will be inlined into an inode as well. Therefore, this statistic doesn't represent logical savings either, because it doesn't take compression into account. To report the logical savings, total logical size for all inlined files should be tracked.

To avoid any confusion, we plan to rename this statistic to “Total inline data” in the next version of OneFS. We also plan to show more useful information about total logical data of inlined files, in addition to “Total inline data”.

For more information about the reporting of data reduction features, see the white paper   PowerScale OneFS: Data Reduction and Storage Efficiency on the Info Hub.

Author: Yunlong Zhang, Principal Engineering Technologist

Among the objectives of OneFS reduction and efficiency reporting is to provide ‘industry standard’ statistics, allowing easier comprehension of cluster efficiency. It’s an ongoing process, and prior to OneFS 9.2 there was limited tracking of certain filesystem statistics – particularly application physical and filesystem logical – which meant that data reduction and storage efficiency ratios had to be estimated. This is no longer the case, and OneFS 9.2 and later provides accurate data reduction and efficiency metrics at a per-file, quota, and cluster-wide granularity.

The following table provides descriptions for the various OneFS reporting metrics, while also attempting to rationalize their naming conventions with other general industry terminology:

So let’s take these metrics and look at what they represent and how they’re calculated.

• Application logical, or protected logical, is the application data that can be written to the cluster, irrespective of where it’s stored.
• Removing the sparse data from application logical results in filesystem logical, also known simply as logical data or effective. This can be data that was always sparse, was zero block eliminated, or data that has been tiered off-cluster by means of CloudPools, and so on.

  (Note that filesystem logical was not accurately tracked in releases prior to OneFS 9.2, so metrics prior to this were somewhat estimated.)

• Next, data reduction techniques such as compression and deduplication further reduce filesystem logical to application physical, or pre-protected physical. This is the physical size of the application data residing on the filesystem drives, and does not include metadata, protection overhead, or data moved to the cloud.

• Filesystem physical is application physical with data protection overhead added – including inode, mirroring, and FEC blocks. Filesystem physical is also referred to as protected physical.

• The data reduction ratio is the amount that’s been reduced from the filesystem logical down to the application physical.

• Finally, the storage efficiency ratio is the filesystem logical divided by the filesystem physical.

With the enhanced data reduction reporting in OneFS 9.2 and later, the actual statistics themselves are largely the same, just calculated more accurately.

The storage efficiency data was available in releases prior to OneFS 9.2, albeit somewhat estimated, but the data reduction metrics were introduced with OneFS 9.2.

The following tools are available to query these reduction and efficiency metrics at file, quota, and cluster-wide granularity:

Note that the ‘isi_cstats’ CLI command provides some additional, behind-the-scenes details. The interface goes through platform API to fetch these stats.

The ‘isi statistics data-reduction’ CLI command is the most comprehensive of the data reduction reporting CLI utilities. For example:

# isi statistics data-reduction
                      Recent Writes Cluster Data Reduction
                           (5 mins)
--------------------- ------------- ----------------------
Logical data                  6.18M                  6.02T
Zero-removal saved                0                      -
Deduplication saved          56.00k                  3.65T
Compression saved             4.16M                  1.96G
Preprotected physical         1.96M                  2.37T
Protection overhead           5.86M                910.76G
Protected physical            7.82M                  3.40T
Zero removal ratio         1.00 : 1                      -
Deduplication ratio        1.01 : 1               2.54 : 1
Compression ratio          3.12 : 1               1.02 : 1
Data reduction ratio       3.15 : 1               2.54 : 1
Inlined data ratio         1.04 : 1               1.00 : 1
Efficiency ratio           0.79 : 1               1.77 : 1

The ‘recent writes’ data in the first column provides precise statistics for the five-minute period prior to running the command. By contrast, the ‘cluster data reduction’ metrics in the second column are slightly less real-time but reflect the overall data and efficiencies across the cluster. Be aware that, in OneFS 9.1 and earlier, the right-hand column metrics are designated by the ‘Est’ prefix, denoting an estimated value. However, in OneFS 9.2 and later, the ‘logical data’ and ‘preprotected physical’ metrics are tracked and reported accurately, rather than estimated.

The ratio data in each column is calculated from the values above it. For instance, to calculate the data reduction ratio, the ‘logical data’ (effective) is divided by the ‘preprotected physical’ (usable) value. From the output above, this would be:

6.02 / 2.37 = 1.76              Or a Data Reduction ratio of 2.54:1

Similarly, the ‘efficiency ratio’ is calculated by dividing the ‘logical data’ (effective) by the ‘protected physical’ (raw) value. From the output above, this yields:

6.02 / 3.40 = 0.97              Or an Efficiency ratio of 1.77:1

OneFS SmartQuotas reports the capacity saving from in-line data reduction as a storage efficiency ratio. SmartQuotas reports efficiency as a ratio across the desired data set as specified in the quota path field. The efficiency ratio is for the full quota directory and its contents, including any overhead, and reflects the net efficiency of compression and deduplication. On a cluster with licensed and configured SmartQuotas, this efficiency ratio can be easily viewed from the WebUI by navigating to File System > SmartQuotas > Quotas and Usage. In OneFS 9.2 and later, in addition to the storage efficiency ratio, the data reduction ratio is also displayed. 

Similarly, the same data can be accessed from the OneFS command line by using the ‘isi quota quotas list’ CLI command. For example:

# isi quota quotas list
Type    AppliesTo   Path  Snap  Hard   Soft  Adv  Used   Reduction  Efficiency
----------------------------------------------------------------------------
directory DEFAULT    /ifs   No    -     -      -    6.02T 2.54 : 1   1.77 : 1
----------------------------------------------------------------------------

Total: 1

More detail, including both the physical (raw) and logical (effective) data capacities, is also available by using the ‘isi quota quotas view <path> <type>’ CLI command. For example:

# isi quota quotas view /ifs directory
                        Path: /ifs
                        Type: directory
                   Snapshots: No
                    Enforced: No
                   Container: No
                      Linked: No
                       Usage
                           Files: 5759676
         Physical(With Overhead): 6.93T
        FSPhysical(Deduplicated): 3.41T
         FSLogical(W/O Overhead): 6.02T
        AppLogical(ApparentSize): 6.01T
                   ShadowLogical: -
                    PhysicalData: 2.01T
                      Protection: 781.34G
     Reduction(Logical/Data): 2.54 : 1
Efficiency(Logical/Physical): 1.77 : 1

To configure SmartQuotas for in-line data efficiency reporting, create a directory quota at the top-level file system directory of interest, for example /ifs. Creating and configuring a directory quota is a simple procedure and can be performed from the WebUI by navigating to File System > SmartQuotas > Quotas and Usage and selecting Create a Quota. In the Create a quota dialog, set the Quota type to ‘Directory quota’, add the preferred top-level path to report on, select ’Application logical size’ for Quota Accounting, and set the Quota Limits to ‘Track storage without specifying a storage limit’. Finally, click the ‘Create Quota’ button to confirm the configuration and activate the new directory quota.

The efficiency ratio is a single, current-in time efficiency metric that is calculated per quota directory and includes the sum of in-line compression, zero block removal, in-line dedupe, and SmartDedupe. This is in contrast to a history of stats over time, as reported in the ‘isi statistics data-reduction’ CLI command output, described above. As such, the efficiency ratio for the entire quota directory will reflect what is actually there.

Author: Nick Trimbee

Among the features and functionality delivered in the new OneFS 9.4 release is the promotion of in-line dedupe to enabled by default, further enhancing PowerScale’s dollar-per-TB economics, rack density and value.

Part of the OneFS data reduction suite, in-line dedupe initially debuted in OneFS 8.2.1. However, it was enabled manually, so many customers simply didn’t use it. But with this enhancement, new clusters running OneFS 9.4 now have in-line dedupe enabled by default.

That said, any clusters that upgrade to 9.4 will not see any change to their current in-line dedupe config during upgrade. Also, there is also no change to the behavior for in-line compression, which remains enabled by default in all OneFS versions from 8.1.3 onwards.

But before we examine the-under-the-hood changes in OneFS 9.4, let’s have a quick dedupe refresher.

Currently, OneFS in-line data reduction, which encompasses compression, dedupe, and zero block removal, is supported on the F900, F600, and F200 all-flash nodes, plus the F810, H5600, H700/7000, and A300/3000 Gen6.x chassis.

Within the OneFS data reduction pipeline, zero block removal is performed first, followed by dedupe, and then compression. This order allows each phase to reduce the scope of work each subsequent phase.

Unlike SmartDedupe, which performs deduplication once data has been written to disk, or post-process, in-line dedupe acts in real time, deduplicating data as is ingested into the cluster. Storage efficiency is achieved by scanning the data for identical blocks as it is received and then eliminating the duplicates.

When in-line dedupe discovers a duplicate block, it moves a single copy of the block to a special set of files known as shadow stores. These are file-system containers that allow data to be stored in a sharable manner. As such, files stored under OneFS can contain both physical data and pointers, or references, to shared blocks in shadow stores.

Shadow stores are similar to regular files but are hidden from the file system namespace, so they cannot be accessed through a pathname. A shadow store typically grows to a maximum size of 2 GB, which is around 256 K blocks, and each block can be referenced by 32,000 files. If the reference count limit is reached, a new block is allocated, which may or may not be in the same shadow store. Also, shadow stores do not reference other shadow stores. And snapshots of shadow stores are not permitted because the data contained in shadow stores cannot be overwritten.

When a client writes a file to a node pool configured for in-line dedupe on a cluster, the write operation is divided up into whole 8 KB blocks. Each block is hashed, and its cryptographic ‘fingerprint’ is compared against an in-memory index for a match. At this point, one of the following will happen:

1. If a match is discovered with an existing shadow store block, a byte-by-byte comparison is performed. If the comparison is successful, the data is removed from the current write operation and replaced with a shadow reference.
2. When a match is found with another LIN, the data is written to a shadow store instead and is replaced with a shadow reference. Next, a work request is generated and queued that includes the location for the new shadow store block, the matching LIN and block, and the data hash. A byte-by-byte data comparison is performed to verify the match and the request is then processed.
3. If no match is found, the data is written to the file natively and the hash for the block is added to the in-memory index.

For in-line dedupe to perform on a write operation, the following conditions need to be true:

• In-line dedupe must be globally enabled on the cluster.
• The current operation is writing data (not a truncate or write zero operation).
• The no_dedupe flag is not set on the file.
• The file is not a special file type, such as an alternate data stream (ADS) or an EC (endurant cache) file.
• Write data includes fully overwritten and aligned blocks.
• The write is not part of a rehydrate operation.
• The file has not been packed (containerized) by small file storage efficiency (SFSE).

 OneFS in-line dedupe uses the 128-bit CityHash algorithm, which is both fast and cryptographically strong. This contrasts with the OneFS post-process SmartDedupe, which uses SHA-1 hashing.

Each node in a cluster with in-line dedupe enabled has its own in-memory hash index that it compares block fingerprints against. The index lives in system RAM and is allocated using physically contiguous pages and is accessed directly with physical addresses. This avoids the need to traverse virtual memory mappings and does not incur the cost of translation lookaside buffer (TLB) misses, minimizing dedupe performance impact.

The maximum size of the hash index is governed by a pair of sysctl settings, one of which caps the size at 16 GB, and the other which limits the maximum size to 10% of total RAM. The strictest of these two constraints applies. While these settings are configurable, the recommended best practice is to use the default configuration. Any changes to these settings should only be performed under the supervision of Dell support.

Since in-line dedupe and SmartDedupe use different hashing algorithms, the indexes for each are not shared directly. However, the work performed by each dedupe solution can be used by each other. For instance, if SmartDedupe writes data to a shadow store, when those blocks are read, the read-hashing component of in-line dedupe sees those blocks and indexes them.

When a match is found, in-line dedupe performs a byte-by-byte comparison of each block to be shared to avoid the potential for a hash collision. Data is prefetched before the byte-by-byte check and is compared against the L1 cache buffer directly, avoiding unnecessary data copies and adding minimal overhead. Once the matching blocks are compared and verified as identical, they are shared by writing the matching data to a common shadow store and creating references from the original files to this shadow store.

In-line dedupe samples every whole block that is written and handles each block independently, so it can aggressively locate block duplicity. If a contiguous run of matching blocks is detected, in-line dedupe merges the results into regions and processes them efficiently.

In-line dedupe also detects dedupe opportunities from the read path, and blocks are hashed as they are read into L1 cache and inserted into the index. If an existing entry exists for that hash, in-line dedupe knows there is a block-sharing opportunity between the block it just read and the one previously indexed. It combines that information and queues a request to an asynchronous dedupe worker thread. As such, it is possible to deduplicate a data set purely by reading it all. To help mitigate the performance impact, the hashing is performed out-of-band in the prefetch path, rather than in the latency-sensitive read path.

The original in-line dedupe control path design had its limitations, since it did not provide gconfig control settings for the default-disabled in-line dedupe. The previous control-path logic had no gconfig control settings for default-disabled in-line dedupe. But in OneFS 9.4, there are now two separate features that interact together to distinguish between a new cluster or an upgrade to an existing cluster configuration:

For the first feature, upon upgrade to 9.4 on an existing cluster, if there is no in-line dedupe config present, the upgrade explicitly sets it to disabled in gconfig. This has no effect on an existing cluster since it’s already disabled. Similarly, if the upgrading cluster already has an existing in-line dedupe setting in gconfig, OneFS takes no action.

For the other half of the functionality, when booting OneFS 9.4, a node looks in gconfig to see if there’s an in-line dedupe setting. If no config is present, OneFS enables it by default. Therefore, new OneFS 9.4 clusters automatically enable dedupe, and existing clusters retain their legacy setting upon upgrade.

Since the in-line dedupe configuration is binary (either on or off across a cluster), you can easily control it manually through the OneFS command line interface (CLI). As such, the isi dedupe inline settings modify CLI command can either enable or disable dedupe at will—before, during, or after the upgrade. It doesn’t matter.

For example, you can globally disable in-line dedupe and verify it using the following CLI command:

# isi dedupe inline settings viewMode: enabled# isi dedupe inline settings modify –-mode disabled
# isi dedupe inline settings view
Mode: disabled

Similarly, the following syntax enables in-line dedupe:

# isi dedupe inline settings view
Mode: disabled
# isi dedupe inline settings modify –-mode enabled
# isi dedupe inline settings view
Mode: enabled

While there are no visible userspace changes when files are deduplicated, if deduplication has occurred, both the disk usage and the physical blocks metrics reported by the isi get –DD CLI command are reduced. Also, at the bottom of the command’s output, the logical block statistics report the number of shadow blocks. For example:

Metatree logical blocks:    zero=260814 shadow=362 ditto=0 prealloc=0 block=2 compressed=0

In-line dedupe can also be paused from the CLI:

# isi dedupe inline settings modify –-mode paused
# isi dedupe inline settings view
Mode: paused

However, it’s worth noting that this global setting states what you’d like to happen, after which each node attempts to enact the new configuration. However, it can’t guarantee the change, because not all node types support in-line dedupe. For example, the following output is from a heterogenous cluster with an F200 three-node pool supporting in-line dedupe, and an H400 four-node pool not supporting it.

Here, we can see that in-line dedupe is globally enabled on the cluster:

# isi dedupe inline settings view
Mode: enabled

However, you can use the isi_for_array isi_inline_dedupe_status command to display the actual setting and state of each node:

# isi dedupe inline settings view
Mode: enabled
# isi_for_array -s isi_inline_dedupe_status
1: OK Node setting enabled is correct
2: OK Node setting enabled is correct
3: OK Node setting enabled is correct
4: OK Node does not support inline dedupe and current is disabled
5: OK Node does not support inline dedupe and current is disabled
6: OK Node does not support inline dedupe and current is disabled
7: OK Node does not support inline dedupe and current is disabled

Also, any changes to the dedupe configuration are also logged to /var/log/messages, you can find them by grepping for inline_dedupe.

In a nutshell, in-line compression has always been enabled by default since its introduction in OneFS 8.1.3. For new clusters running 9.4 and above, in-line dedupe is on by default. For clusters running 9.3 and earlier, in-line dedupe remains disabled by default. And existing clusters that upgrade to 9.4 will not see any change to their current in-line dedupe config during upgrade.

And here’s the OneFS in-line data reduction platform support matrix for good measure: