CSM 1.8 Release is Here!
Fri, 22 Sep 2023 21:29:12 -0000
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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