Looking Ahead: Dell Container Storage Modules 1.2
Mon, 21 Mar 2022 14:42:31 -0000
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The quarterly update for Dell CSI Drivers & Dell Container Storage Modules (CSM) is here! Here’s what we’re planning.
CSM Features
New CSM Operator!
Dell Container Storage Modules (CSM) add data services and features that are not in the scope of the CSI specification today. The new CSM Operator simplifies the deployment of CSMs. With an ever-growing ecosystem and added features, deploying a driver and its affiliated modules need to be carefully studied before beginning the deployment.
The new CSM Operator:
- Serves as a one-stop-shop for deploying all Dell CSI driver and Container Storage Modules
- Simplifies the install and upgrade operations
- Leverages the Operator framework to give a clear status of the deployment of the resources
- Is certified by Red Hat OpenShift
In the short/middle term, the CSM Operator will deprecate the experimental CSM Installer.
Replication support with PowerScale
For disaster recovery protection, PowerScale implements data replication between appliances by means of the the SyncIQ feature. SyncIQ replicates the data between two sites, where one is read-write while the other is read-only, similar to Dell storage backends with async or sync replication.
The role of the CSM replication module and underlying CSI driver is to provision the volume within Kubernetes clusters and prepare the export configurations, quotas, and so on.
CSM Replication for PowerScale has been designed and implemented in such a way that it won’t collide with your existing Superna Eyeglass DR utility.
A live-action demo will be posted in the coming weeks on our VP YouTube channel: https://www.youtube.com/user/itzikreich/.
CSI features
Across the portfolio
In this release, each CSI driver:
- Supports OpenShift 4.9
- Supports Kubernetes 1.23
- Supports the CSI Spec 1.5
- Updates the latest UBI-minimal image
- Supports fsGroupPolicy
fsGroupPolicy support
Kubernetes v1.19 introduced the fsGroupPolicy to give more control to the CSI driver over the permission sets in the securityContext.
There are three possible options:
- None -- which means that the fsGroup directive from the securityContext will be ignored
- File -- which means that the fsGroup directive will be applied on the volume. This is the default setting for NAS systems such as PowerScale or Unity-File.
- ReadWriteOnceWithFSType -- which means that the fsGroup directive will be applied on the volume if it has fsType defined and is ReadWriteOnce. This is the default setting for block systems such as PowerMax and PowerStore-Block.
In all cases, Dell CSI drivers let kubelet perform the change ownership operations and do not do it at the driver level.
Standalone Helm install
Drivers for PowerFlex and Unity can now be installed with the help of the install scripts we provide under the dell-csi-installer directory.
A standalone Helm chart helps to easily integrate the driver installation with the agent for Continuous Deployment like Flux or Argo CD.
Note: To ensure that you install the driver on a supported Kubernetes version, the Helm charts take advantage of the kubeVersion field. Some Kubernetes distributions use labels in kubectl version (such as v1.21.3-mirantis-1 and v1.20.7-eks-1-20-7) that require manual editing.
Volume Health Monitoring support
Drivers for PowerFlex and Unity implement Volume Health Monitoring.
This feature is currently in alpha in Kubernetes (in Q1-2022), and is disabled with a default installation.
Once enabled, the drivers will expose the standard storage metrics, such as capacity usage and inode usage through the Kubernetes /metrics endpoint. The metrics will flow natively in popular dashboards like the ones built-in OpenShift Monitoring:
Pave the way for full open source!
All Dell drivers and dependencies like gopowerstore, gobrick, and more are now on Github and will be fully open-sourced. The umbrella project is and remains https://github.com/dell/csm, from which you can open tickets and see the roadmap.
Google Anthos 1.9
The Dell partnership with Google continues, and the latest CSI drivers for PowerScale and PowerStore support Anthos v1.9.
NFSv4 POSIX and ACL support
Both CSI PowerScale and PowerStore now allow setting the default permissions for the newly created volume. To do this, you can use POSIX octal notation or ACL.
- In PowerScale, you can use plain ACL or built-in values such as private_read, private, public_read, public_read_write, public or custom ones;
- In PowerStore, you can use the custom ones such as A::OWNER@:RWX, A::GROUP@:RWX, and A::OWNER@:rxtncy.
Useful links
For more details you can:
- Watch these great CSM demos on our VP YouTube channel: https://www.youtube.com/user/itzikreich/
- Read the FAQs
- Subscribe to Github notification and be informed of the latest releases on: https://github.com/dell/csm
- Ask for help or chat with us on Slack
Author: Florian Coulombel
Related Blog Posts
CSM 1.8 Release is Here!
Fri, 22 Sep 2023 21:29:12 -0000
|Read Time: 0 minutes
Introduction
This is already the third release of Dell Container Storage Modules (CSM)!
The official changelog is available in the CHANGELOG directory of the CSM repository.
CSI Features
Supported Kubernetes distributions
The newly supported Kubernetes distributions are :
- Kubernetes 1.28
- OpenShift 4.13
SD-NAS support for PowerMax and PowerFlex
Historically, PowerMax and PowerFlex are Dell’s high-end and SDS for block storage. Both of these backends recently introduced support for software defined NAS.
This means that the respective CSI drivers can now provision PVC with the ReadWriteMany access mode for the volume type file. In other words, thanks to the NFS protocol different nodes from the Kubernetes cluster can access the same volume concurrently. This feature is particularly useful for applications, such as log management tools like Splunk or Elastic Search, that need to process logs coming from multiple Pods.
CSI Specification compliance
Storage capacity tracking
Like PowerScale in v1.7.0, PowerMax and Dell Unity allow you to check the storage capacity on a node before deploying storage to that node. This isn't that relevant in the case of shared storage, because shared storage generally will always show the same capacity to each node in the cluster. However, it could prove useful if the array lacks available storage.
Using this feature, an object from the CSIStorageCapacity type is created by the CSI driver in the same namespace as the CSI driver, one for each storageClass.
An example:
kubectl get csistoragecapacities -n unity # This shows one object per storageClass.
Volume Limits
The Volume Limits feature is added to both PowerStore and PowerFlex. All Dell storage platforms now implement this feature.
This option limits the maximum number of volumes to which a Kubernetes worker node can connect. This can be configured on a per-node basis, or cluster-wide. Setting this variable to zero disables the limit.
Here are some PowerStore examples.
Per node:
kubectl label node <node name> max-powerstore-volumes-per-node=<volume_limit>
For the entire cluster (all worker nodes):
Specify maxPowerstoreVolumesPerNode or maxVxflexVolumesPerNode in the values.yaml file upon Helm installation.
If you opted-in for the CSP Operator deployment, you can control it by specifying X_CSI_MAX_VOLUMES_PER_NODES in the CRD.
Useful links
Stay informed of the latest updates of the Dell CSM eco-system by subscribing to:
- The Dell CSM Github repository
- Our DevOps & Automation Youtube playlist
- Slack (under the Dell Infrastructure namespace)
- Live streaming on Twitch
Author: Florian Coulombel
CSM 1.7 Release is Here!
Fri, 30 Jun 2023 13:42:36 -0000
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Introduction
The second release of 2023 for Kubernetes CSI Driver & Dell Container Storage Modules (CSM) is here!
The official changelog is available in the CHANGELOG directory of the CSM repository.
As you may know, Dell Container Storage Modules (CSM) bring powerful enterprise storage features and functionality to your Kubernetes workloads running on Dell primary storage arrays, and provide easier adoption of cloud native workloads, improved productivity, and scalable operations. Read on to learn more about what’s in this latest release.
CSI features
Supported Kubernetes distributions
The newly supported Kubernetes distributions are:
- Kubernetes 1.27
- OpenShift 4.12
- Amazon EKS Anywhere
- k3s on Debian
CSI PowerMax
For the last couple of versions, the CSI PowerMax reverseproxy is enabled by default. The TLS certificate secret creation is now pre-packaged using cert-manager, to avoid manual steps for the administrator.
A volume can be mounted to a Pod as `readOnly`. This is the default behavior for a `configMap` or `secret`. That option is now also supported for RawBlock devices.
apiVersion: v1 kind: Pod metadata: name: task-pv-pod spec: volumes: - name: task-pv-storage persistentVolumeClaim: claimName: task-pv-claim # What ever is the accessMode it will be read-only for the Pod readOnly: true ...
CSM v1.5 introduced the capacity to provision Fibre Channel LUNs to Kubernetes worker nodes through VMware Raw Device Mapping. One limitation of the RDM/LUN was that it was sticky to a single ESXi host, meaning that the Pod could not move to another worker node.
The auto-RDM feature works at the HostGroup level in PowerMax and therefore supports clusters with multiple ESXi hosts.
We are exposing the host I/O limits on the storage groups parameter using the StorageClass. The Host I/O limit is here to implement QoS at the worker node level and to prevent any noisy neighbor behavior.
CSI PowerScale
Storage Capacity Tracking is used by the Kubernetes scheduler to make sure that the node and backend storage have enough capacity for Pod/PVC.
The user can now set Quota limit parameters from the PVC and StorageClass requests. This allows the user to have better control of the quota parameters (including Soft Limit, AdvisoryLimit, Softgrace period) attached to each PVC
The PVC settings take precedence if quota limit values are specified in both StorageClass and PVC.
CSM features
CSM Operator
One can now use the CSM Operator to install Dell Unity and PowerMax CSI drivers and affiliated modules.
The CSM Operator now provides CSM resiliency and CSM-Replication for CSI-PowerFlex.
A detailed matrix of supported CSM components is available here.
CSM Installation Wizard
The CSM Installation Wizard is the easiest and most straight forward way to install the Dell CSI drivers and Container Storage Modules.
In this release, we are adding support for Dell Unity, PowerScale, and PowerFlex.
To keep it simple, we removed the option to install the driver and modules in separate namespaces.
CSM Authorization
In this release of CSM, Secrets Encryption is enabled by default.
- All secrets are encrypted by default, using the AES-CBC key type.
- After installation/upgrade, all secrets will be encrypted.
- AES-CBC is the default key type.
- AES-CBC is the only supported key type.
CSM Replication
When you use CSM replication, two volumes are created: the active volume and the replica. Prior to CSM v1.7, if you removed the two PVs, the physical replica wasn't deleted.
Now on PV deletion, we cascade the removal to all objects, including the replica block volumes in PowerStore, PowerMax, and PowerFlex, so that there are no more orphan volumes.
Useful links
Stay informed of the latest updates of the Dell CSM eco-system by subscribing to:
- The Dell CSM Github repository
- Our DevOps & Automation Youtube playlist
- Slack (under the Dell Infrastructure namespace)
Author: Florian Coulombel