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Dell Unity NAS servers are assigned to a single SP. All file systems serviced by a NAS server will have their I/O processed by the SP on which the NAS server is resident or current. If multiple NAS servers are required, load balance NAS servers by creating them on SP A and SP B such that the front-end NFS I/O is distributed evenly between SPs. Because both SPs can be used simultaneously, do not overprovision either of the SPs so that the peer SP does not become overloaded if an SP failover occurs.
Because each NAS server is logically separate, NFS clients of a NAS server cannot access data on another NAS server. Logically separate NAS servers can provide database isolation and protection across multiple NFS clients (database servers).
Unity NAS servers must have one or more interfaces that are created on one or more Ethernet ports from either the onboard embedded four port card or optional I/O modules. Should a failure occur on a single-link Unity network, the system does not initiate an SP failover to the peer SP. In an Oracle environment, such a failure would cause the database to appear unresponsive. Therefore, Dell Technologies recommends configuring highly available NAS Server networks for Oracle environments.
Highly available Unity network interfaces can be configured either as link aggregations or fail-safe networks. Link aggregations combine multiple Ethernet ports from either the onboard four-port card or optional I/O modules into one logical link. Link aggregations provide link redundancy and increased bandwidth. If a link in the link aggregate fails, traffic is automatically routed to surviving links in the link aggregate. For information about creating a link aggregation, see the section Unity link aggregation configuration.
Fail-safe networking (FSN) was made available starting with OE version 4.2.1. FSN is a high availability feature that extends link failover by supporting switch-level redundancy. FSN can consist of Ethernet ports, link aggregations, or both.
For more information about link aggregations, FSN, or high availability and redundancy, reference the Dell Unity: NAS Capabilities, and Dell Unity; High Availability white papers on Dell Technologies Info Hub,
For brevity, Unity NAS Server network interfaces configured as Fail-safe networks are not discussed in this document.
Dell Unity storage supports NFSv3 through NFSv4.1, including secure NFS.
All Dell Unity OE versions support Oracle dNFS in single-node configurations. Starting with OE version 4.2, Oracle Real Application Clusters (RAC) are also supported.
Unity 4.2 and newer versions, and Oracle dNFS starting with Oracle 12c have support for NFSv3, NFSv4, and NFSv4.1 protocols, with the following exceptions:
Therefore, do not configure pNFS in Oracle, and use the NFSv3 protocol if dNFS is used.
Note: pNFS refers to a protocol to access an NFS server, while dNFS refers to a driver built into the Oracle Disk Manager (ODM).
This section assumes a link aggregation has been created.
To create a NAS server in Unity, perform the following steps in Unisphere:
If no Link Aggregations appear in the list of available interfaces, it is because no Link Aggregations have been configured in Unity. For information about creating link aggregations in Unity, see the section Creating Unity link aggregations.
Notes:
1) The Ethernet switch interfaces that are cabled to the port members of a Unity Link Aggregation must be members of a port channel on the switch. See Figure 54 and Figure 55 in the section Unity link aggregation and Ethernet switch port channel configuration.
2) Dell Technologies recommends using two TOR switches for redundancy in production environments. The lab that we used for this paper is configured with a single TOR switch.
3) When you select the Ethernet Port interface, Unity will automatically assign the corresponding Ethernet Port from the peer SP to the peer SP interface.
Note: Specifying a value for VLAN ID instructs Unity to tag the network frames with the specified VLAN ID. If you are unsure if a VLAN ID should be specified, ask the Network Administrator responsible for the candidate IP address of this Unity NAS server interface.
If you select Edit to the right of VLAN ID, the following cautionary note will be displayed.
Our lab uses VLANs, and tagged switch interfaces cabled to the Unity interfaces. Therefore, Edit > Yes was selected and the appropriate VLAN ID for our environment was specified (see Figure 14).
VLAN ID should be set to None if:
If the switch interfaces connected to the Unity interfaces are tagged to the VLAN of the IP address (fff.fff.fff.fff) of the Unity interface, set the VLAN ID (see Figure 16).
After a NAS server is created, the Dell Unity NFS file systems and then Dell Unity NFS shares can be created. See sections Dell Unity NFS file system for more information.
To increase throughput on the NAS server, additional interfaces (single or link aggregate) can be added to the NAS server. For information about adding more network interfaces to a Unity NAS server, see the section: Adding additional interfaces to Unity NAS Servers.
There are several use cases for using multiple interfaces in a Unity NAS Server. Two of them are:
If either of these use cases exist, consider adding one or more interfaces to the Unity NAS Server. Extra interaces added to the NAS server are added as a nonpreferred network interface.
To add additional interfaces to the Unity NAS Server, perform the following in Unisphere:
Note: NAS server interfaces can be either configured as production, or backup and DR testing interfaces. The type of interface dictates the type of activity that can be performed. Table 8 displays the characteristics of the interface types.
Interface type | Characteristics |
Production |
|
Backup and DR test |
|
Note: To avoid a network interface single point of failure, Dell Technologies recommends selecting a highly available network interface when the NAS Server is used to host an Oracle database.
If no highly available interface appears in the list of available interfaces, it is because no highly available interface has been configured in Unity. For information about creating Unity link aggregations, see the section Configuring LACP—NAS server Creating Unity link aggregations.
Notes:
1) Ethernet switch interfaces that are cabled to the Unity Link Aggregation port members must be members of a switch port channel. See Figure 21 and the section Unity link aggregate and Ethernet switch port channel configuration.
2) Dell Technologies recommends using two TOR switches for redundancy in production environments. The lab that we used for this paper is configured with a single TOR switch. Also, see the note in the section Dell Unity file system and Oracle ASM disks regarding redundancy considerations.
3) When you select the Ethernet Port interface, Unity automatically configures the same interface on the peer SP.
Note: For more information about specifying a VLAN ID, see step 4 in the section Creating a NAS server and adding a link aggregation network interface.
Repeat this section if additional link aggregate network interfaces are needed in the NAS Server.
The NAS Server interfaces in Figure 21 were configured for this paper:
Link Aggregation Ocp 0 0 is the preferred interface, while Link Aggregation Iom 1 0 and Link Aggregation Iom 1 2 are nonpreferred interfaces.