PowerScale

Code features for PowerScale Driver

Multicluster support

You can connect a single CSI-PowerScale driver with multiple PowerScale clusters.

Pre-Requisites:

  1. Creation of secret.yaml with credentials related to one or more Clusters.
  2. Creation of (at least) one Storage class for each cluster.
  3. Creation of custom-volumesnapshot classes with proper isiPath matching corresponding storage classes.
  4. Inclusion of cluster name in volume handle, if you want to provision existing static volumes.

Consuming existing volumes with static provisioning

You can use existing volumes from the PowerScale array as Persistent Volumes in your Kubernetes, perform the following steps:

  1. Open your volume in One FS, and take a note of volume-id.
  2. Create PersistentVolume and use this volume-id as a volumeHandle in the manifest. Modify other parameters according to your needs.
  3. In the following example, the PowerScale cluster accessZone is assumed as ‘System’, storage class as ‘isilon’, cluster name as ‘pscale-cluster’ and volume’s internal name as ‘isilonvol’. The volume-handle should be in the format of <volume_name>=_=_=<export_id>=_=_=<access_zone_name>=_=_=<cluster_name>
  4. If Quotas are enabled in the driver, it is required to add the Quota ID to the description of the NFS export in this format: CSI_QUOTA_ID:sC-kAAEAAAAAAAAAAAAAQEpVAAAAAAAA
  5. Quota ID can be identified by querying the PowerScale system.
apiVersion: v1
kind: PersistentVolume
metadata:
  name: isilonstaticpv
  namespace: default
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: isilon
  csi:
    driver: csi-isilon.dellemc.com
    volumeAttributes:
      Path: "/ifs/data/csi/isilonvol"
      Name: "isilonvol"
      AzServiceIP: 'XX.XX.XX.XX'
    volumeHandle: isilonvol=_=_=652=_=_=System=_=_=pscale-cluster
  claimRef:
    name: isilonstaticpvc
    namespace: default
  1. Create PersistentVolumeClaim to use this PersistentVolume.
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: isilonstaticpvc
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
  volumeName: isilonstaticpv
  storageClassName: isilon
  1. Then use this PVC as a volume in a pod.
apiVersion: v1
kind: Pod
metadata:
  name: static-prov-pod
spec:
  containers:
    - name: test
      image: docker.io/centos:latest
      command: [ "/bin/sleep", "3600" ]
      volumeMounts:
        - mountPath: "/data0"
          name: pvol
  volumes:
    - name: pvol
      persistentVolumeClaim:
        claimName: isilonstaticpvc
  1. After the pod becomes Ready and Running, you can start to use this pod and volume.

PVC Creation Feature

The following yaml content can be used to create a PVC without referring any PV.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: testvolume
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
  storageClassName: isilon

Volume Snapshot Feature

The CSI PowerScale driver version 2.0 and later supports managing v1 snapshots.

In order to use Volume Snapshots, ensure the following components have been deployed to your cluster:

  • Kubernetes Volume Snapshot CRDs
  • Volume Snapshot Controller

For general use, update the snapshot controller YAMLs with an appropriate namespace before installing. For example, on a Vanilla Kubernetes cluster, update the namespace from default to kube-system before issuing the kubectl create command.

Volume Snapshot Class

During the installation of CSI PowerScale driver version 2.0 and higher, no default Volume Snapshot Class will get created.

The following are the manifests for the Volume Snapshot Class:

  1. VolumeSnapshotClass

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshotClass
metadata:
  name: "isilon-snapclass"
driver: csi-isilon.dellemc.com
#The deletionPolicy of a volume snapshot class can either be Retain or Delete
#If the deletionPolicy is Delete, then the underlying storage snapshot is deleted along with the VolumeSnapshotContent object.
#If the deletionPolicy is Retain, then both the underlying snapshot and VolumeSnapshotContent remain
deletionPolicy: Delete
parameters:
  #IsiPath should match with respective storageClass IsiPath
  IsiPath: "/ifs/data/csi"

The following is a sample manifest for creating a Volume Snapshot using the v1 snapshot APIs; The following snippet assumes that the persistent volume claim name is testvolume.

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: pvcsnap
  namespace: default
spec:
  volumeSnapshotClassName: isilon-snapclass
  source:
    persistentVolumeClaimName: testvolume

Once the VolumeSnapshot has been successfully created by the CSI PowerScale driver, a VolumeSnapshotContent object is automatically created. Once the status of the VolumeSnapshot object has the readyToUse field set to true , it is available for use.

The following is the relevant section of VolumeSnapshot object status:

status:
  boundVolumeSnapshotContentName: snapcontent-xxxxxxxxxxxxx
  creationTime: "2020-07-16T08:42:12Z"
  readyToUse: true

Creating PVCs with Volume Snapshots as Source

The following is a sample manifest for creating a PVC with a VolumeSnapshot as a source:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: createfromsnap
  namespace: default
spec:
  storageClassName: isilon
  dataSource:
    name: pvcsnap
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi

Starting from CSI PowerScale driver version 2.2, different isi paths can be used to create PersistentVolumeClaim from VolumeSnapshot.This means the isi paths of the new volume and the VolumeSnapshot can be different.

Volume Expansion

CSI PowerScale driver version 1.2 and later supports the expansion of Persistent Volumes (PVs). This expansion can be done either online (for example, when a PVC is attached to a node) or offline (for example, when a PVC is not attached to any node).

To use this feature, the storage class that is used to create the PVC must have the attribute allowVolumeExpansion set to true.

The following is a sample manifest for a storage class that allows for Volume Expansion:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: isilon-expand-sc
  annotations:
    storageclass.kubernetes.io/is-default-class: "false"
provisioner: "csi-isilon.dellemc.com"
reclaimPolicy: Delete
parameters:
  ClusterName: <clusterName specified in secret.yaml>
  AccessZone: System
  isiPath: "/ifs/data/csi"
  AzServiceIP : 'XX.XX.XX.XX'
  rootClientEnabled: "true"
allowVolumeExpansion: true
volumeBindingMode: Immediate

To resize a PVC, edit the existing PVC spec and set spec.resources.requests.storage to the intended size. For example, if you have a PVC isilon-pvc-demo of size 3Gi, then you can resize it to 30Gi by updating the PVC.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: isilon-pvc-expansion-demo
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 30Gi # Updated size from 3Gi to 30Gi
  storageClassName: isilon-expand-sc

The Kubernetes Volume Expansion feature can only be used to increase the size of a volume. It cannot be used to shrink a volume.

Volume Cloning Feature

The CSI PowerScale driver version 1.3 and later supports volume cloning. This allows specifying existing PVCs in the dataSource field to indicate a user would like to clone a Volume.

Source and destination PVC must be in the same namespace and have the same Storage Class.

To clone a volume, you must first have an existing PVC:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: existing-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
  storageClassName: isilon

The following is a sample manifest for cloning:

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: volume-from-volume
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  volumeMode: Filesystem
  resources:
    requests:
      storage: 50Gi
  storageClassName: isilon
  dataSource:
    kind: PersistentVolumeClaim
    name: existing-pvc
    apiGroup: ""

Controller HA

CSI PowerScale driver version 1.4.0 and later supports running multiple replicas of the controller pod. Leader election is only applicable for all sidecar containers and driver container will be running in all controller pods. In case of a failure, one of the standby pods becomes active and takes the position of leader. This is achieved by using native leader election mechanisms utilizing kubernetes leases.

Additionally by leveraging pod anti-affinity, no two-controller pods are ever scheduled on the same node.

To increase or decrease the number of controller pods, edit the following value in myvalues.yaml file:

controllerCount: 2

NOTE: The default value for controllerCount is 2. It is recommended to not change this unless really required. Also, if the controller count is greater than the number of available nodes (where the pods can be scheduled), some controller pods will remain in a Pending state.

If you are using the Dell CSM Operator, the value to adjust is:

replicas: 2

For more details about configuring Controller HA using the Dell CSM Operator, see the Dell CSM Operator documentation.

CSI Ephemeral Inline Volume

The CSI PowerScale driver version 1.4.0 and later supports CSI ephemeral inline volumes.

This feature serves as use cases for data volumes whose content and lifecycle are tied to a pod. For example, a driver might populate a volume with dynamically created secrets that are specific to the application running in the pod. Such volumes need to be created together with a pod and can be deleted as part of pod termination (ephemeral). They get defined as part of the pod spec (inline).

At runtime, nested inline volumes follow the lifecycle of their associated pods where the driver handles all phases of volume operations as pods are created and destroyed.

The following is a sample manifest for creating CSI ephemeral Inline Volume in pod manifest with CSI PowerScale driver.

kind: Pod
apiVersion: v1
metadata:
  name: my-csi-app-inline-volume
spec:
  containers:
    - name: my-frontend
      image: busybox
      command: [ "sleep", "100000" ]
      volumeMounts:
        - mountPath: "/data"
          name: my-csi-volume
  volumes:
    - name: my-csi-volume
      csi:
        driver: csi-isilon.dellemc.com
        volumeAttributes:
          size: "2Gi"
          ClusterName: "cluster1"

This manifest creates a pod in a given cluster and attaches a newly created ephemeral inline CSI volume to it.

Note: Storage class is not supported in CSI ephemeral inline volumes and all parameters are driver specific. CSI ephemeral volumes allow users to provide volumeAttributes directly to the CSI driver as part of the Pod spec. These volumeAttributes are supported: size, ClusterName, AccessZone, IsiPath, IsiVolumePathPermissions, AzServiceIP. For reference, check the description of parameters in the following example: isilon.yaml

Topology

Topology Support

CSI PowerScale driver version 1.4.0 and later supports Topology by default which forces volumes to be placed on worker nodes that have connectivity to the backend storage. This results in nodes which have access to PowerScale Array being appropriately labeled. The driver leverages these labels to ensure that the driver components (controller, node) are spawned only on nodes wherein these labels exist.

This covers use cases where:

The CSI PowerScale driver may not be installed or running on some nodes where Users have chosen to restrict the nodes on accessing the PowerScale storage array.

We support CustomTopology which enables users to apply labels for nodes - “csi-isilon.dellemc.com/XX.XX.XX.XX=csi-isilon.dellemc.com” and expect the labels to be honored by the driver.

When “enableCustomTopology” is set to “true”, the CSI driver fetches custom labels “csi-isilon.dellemc.com/XX.XX.XX.XX=csi-isilon.dellemc.com” applied on worker nodes, and uses them to initialize node pod with custom PowerScale FQDN/IP.

Note: Only a single cluster can be configured as part of secret.yaml for custom topology.

Topology Usage

To utilize the Topology feature, create a custom StorageClass with volumeBindingMode set to WaitForFirstConsumer and specify the desired topology labels within allowedTopologies field of this custom storage class. This ensures that the Pod schedule takes advantage of the topology and the selected node has access to provisioned volumes.

Note: Whenever a new storage cluster is being added in secret, even though it is dynamic, the new storage cluster IP address-related label is not added to worker nodes dynamically. The user has to spin off (bounce) driver-related pods (controller and node pods) in order to apply newly added information to be reflected in worker nodes.

Storage Class Example with Topology Support:

# This is a sample manifest for utilizing the topology feature and mount options.
# PVCs created using this storage class will be scheduled 
# only on the nodes with access to Isilon

# Change all instances of <ISILON_IP> to the IP of the PowerScale OneFS API server

# Provide mount options through "mountOptions" attribute 
# to create PVCs with mount options.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: isilon
provisioner: csi-isilon.dellemc.com
reclaimPolicy: Delete
allowVolumeExpansion: true
parameters:
  AccessZone: System
  IsiPath: "/ifs/data/csi"
  # AccessZone groupnet service IP. Update AzServiceIP in values.yaml if different than isiIP.
  #AzServiceIP : 192.168.2.1
  # When a PVC is being created, it takes the storage class' value of "storageclass.rootClientEnabled", 
  # which  determines, when a node mounts the PVC, in NodeStageVolume, whether to add the k8s node to 
  # the "Root clients" field (when true) or "Clients" field (when false) of the NFS export 
  RootClientEnabled: "false"
  # Name of PowerScale cluster where pv will be provisioned
  # This name should match with name of one of the cluster configs in isilon-creds secret
  # If this parameter is not specified, then default cluster config in isilon-creds secret will be considered if available
  #ClusterName: "<cluster_name>"

# volumeBindingMode controls when volume binding and dynamic provisioning should occur.
# Immediate mode indicates that volume binding and dynamic provisioning occurs once the PersistentVolumeClaim is created
# WaitForFirstConsumer mode will delay the binding and provisioning of a PersistentVolume
# until a Pod using the PersistentVolumeClaim is created
volumeBindingMode: WaitForFirstConsumer
# allowedTopologies helps scheduling pod on worker nodes which match all of below expressions
# If enableCustomTopology is set to true in helm values.yaml, then do not specify allowedTopologies
allowedTopologies:
  - matchLabelExpressions:
      - key: csi-isilon.dellemc.com/<ISILON_IP>
        values:
          - csi-isilon.dellemc.com
# specify additional mount options for when a Persistent Volume is being mounted on a node.
# To mount volume with NFSv4, specify mount option vers=4. Make sure NFSv4 is enabled on the Isilon Cluster.
mountOptions: ["<mountOption1>", "<mountOption2>", ..., "<mountOptionN>"]

For additional information, see the Kubernetes Topology documentation.

Support custom networks for NFS I/O traffic

When allowedNetworks is specified for using custom networks to handle NFS traffic, and a user already has workloads scheduled, there is a possibility that it might lead to backward compatibility issues. For example, ControllerUnPublish might not be able to completely remove clients from the NFS exports of previously created pods.

Also, the previous workload will still be using the default network and not custom networks. For previous workloads to use custom networks, the recreation of pods is required.

When csi-powerscale driver creates an NFS export, the traffic flows through the client specified in the export. By default, the client is the network interface for Kubernetes communication (same IP/fqdn as k8s node) by default.

For a cluster with multiple network interfaces and if a user wants to segregate k8s traffic from NFS traffic; you can use the allowedNetworks option. allowedNetworks takes CIDR addresses as a parameter to match the IPs to be picked up by the driver to allow and route NFS traffic.

Volume Limit

The CSI Driver for Dell PowerScale allows users to specify the maximum number of PowerScale volumes that can be used in a node.

The user can set the volume limit for a node by creating a node label max-isilon-volumes-per-node and specifying the volume limit for that node.
kubectl label node <node_name> max-isilon-volumes-per-node=<volume_limit>

The user can also set the volume limit for all the nodes in the cluster by specifying the same to maxIsilonVolumesPerNode attribute in values.yaml.

NOTE:
The default value of maxIsilonVolumesPerNode is 0.
If maxIsilonVolumesPerNode is set to zero, then CO shall decide how many volumes of this type can be published by the controller to the node.

The volume limit specified to maxIsilonVolumesPerNode attribute is applicable to all the nodes in the cluster for which node label max-isilon-volumes-per-node is not set.

Storage Capacity Tracking

CSI for PowerScale driver version 2.8.0 and above supports Storage Capacity Tracking.

This feature helps the scheduler to make more informed choices about where to schedule pods which depends on unbound volumes with late binding (aka “wait for first consumer”). Pods will be scheduled on a node (satisfying the topology constraints) only if the requested capacity is available on the storage array. If such a node is not available, the pods stay in Pending state. This means pods are not scheduled.

Without storage capacity tracking, pods get scheduled on a node satisfying the topology constraints. If the required capacity is not available, volume attachment to the pods fails, and pods remain in ContainerCreating state. Storage capacity tracking eliminates unnecessary scheduling of pods when there is insufficient capacity.

The attribute storageCapacity.enabled in values.yaml can be used to enable/disable the feature during driver installation using helm. This is by default set to true. To configure how often driver checks for changed capacity set storageCapacity.pollInterval attribute. In case of driver installed via operator, this interval can be configured in the sample file provided here. by editing the --capacity-poll-interval argument present in the provisioner sidecar.

Node selector in helm template

Now user can define in which worker node, the CSI node pod daemonset can run (just like any other pod in Kubernetes world).For more information, refer to https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#nodeselector

Similarly, users can define the tolerations based on various conditions like memory pressure, disk pressure and network availability. Refer to https://kubernetes.io/docs/concepts/workloads/controllers/daemonset/#taints-and-tolerations for more information.

Usage of SmartQuotas to Limit Storage Consumption

CSI driver for Dell Isilon handles capacity limiting using SmartQuotas feature.

To use the SmartQuotas feature user can specify the boolean value ’enableQuota’ in myvalues.yaml or my-isilon-settings.yaml.

Let us assume the user creates a PVC with 3 Gi of storage and ‘SmartQuotas’ have already been enabled in PowerScale Cluster.

  • When ’enableQuota’ is set to ’true’

    • The driver sets the hard limit of the PVC to 3Gi.
    • The user adds data of 2Gi to the above said PVC (by logging into POD). It works as expected.
    • The user tries to add 2Gi more data.
    • Driver doesn’t allow the user to enter more data as total data to be added is 4Gi and PVC limit is 3Gi.
    • The user can expand the volume from 3Gi to 6Gi. The driver allows it and sets the hard limit of PVC to 6Gi.
    • User retries adding 2Gi more data (which has been errored out previously).
    • The driver accepts the data.

  • When ’enableQuota’ is set to ‘false’

    • Driver doesn’t set any hard limit against the PVC created.
    • The user adds data of 2Gi to the above said PVC, which is having the size 3Gi (by logging into POD). It works as expected.
    • The user tries to add 2Gi more data. Now the total size of data is 4Gi.
    • Driver allows the user to enter more data irrespective of the initial PVC size (since no quota is set against this PVC)
    • The user can expand the volume from an initial size of 3Gi to 4Gi or more. The driver allows it.

If SmartQuota feature is enabled, user can also set other quota parameters such as Soft Limit , Advisory Limit and soft grace period using storage class yaml file or pvc yaml file.

Storage Class Example with Quota Limit Parameters:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: isilon
provisioner: csi-isilon.dellemc.com
reclaimPolicy: Delete
allowVolumeExpansion: true
parameters:
  # The name of the access zone a volume can be created in
  # Optional: true
  # Default value: default value specified in values.yaml
  # Examples: System, zone1
  AccessZone: System

  # The base path for the volumes to be created on PowerScale cluster.
  # Ensure that this path exists on PowerScale cluster.
  # Allowed values: unix absolute path
  # Optional: true
  # Default value: value specified in values.yaml for isiPath
  # Examples: /ifs/data/csi, /ifs/engineering
  IsiPath: /ifs/data/csi

  #Parameter to set Advisory Limit to quota
  #Optional: true
  #Default value: Limit not Set
  #AdvisoryLimit: "50"
  
  #Parameter to set soft limit to quota
  #Optional: true
  #Default value: Limit not Set
  #SoftLimit: "80"
  
  #Parameter which must be mentioned along with Soft Limit
  #Soft Limit can be exceeded until the grace period
  #Optional: true
  #Default value: Limit not Set
  #SoftGracePrd: "86400"

  # The permissions for isi volume directory path
  # This value overrides the isiVolumePathPermissions attribute of corresponding cluster config in secret, if present
  # Allowed values: valid octal mode number
  # Default value: "0777"
  # Examples: "0777", "777", "0755"
  #IsiVolumePathPermissions: "0777"

  # AccessZone groupnet service IP. Update AzServiceIP if different than endpoint.
  # Optional: true
  # Default value: endpoint of the cluster ClusterName
  #AzServiceIP : 192.168.2.1

  # When a PVC is being created, this parameter determines, when a node mounts the PVC,
  # whether to add the k8s node to the "Root clients" field or "Clients" field of the NFS export
  # Allowed values:
  #   "true": adds k8s node to the "Root clients" field of the NFS export
  #   "false": adds k8s node to the "Clients" field of the NFS export
  # Optional: true
  # Default value: "false"
  RootClientEnabled: "false"

PVC Example with Quota Limit Parameters:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: test-pvc
#Uncomment below 4 lines to set quota limit parameters
#  labels:
#    pvcSoftLimit: "10"
#    pvcAdvisoryLimit: "50"
#    pvcSoftGracePrd : "85400"
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  storageClassName: isilon

Note

  • If quota limit values are specified in both storage class yaml and PVC yaml , then values mentioned in PVC yaml will get precedence.
  • If few parameters are specified in storage class yaml and few in PVC yaml , then both will be combined and applied while quota creation For Example: If advisory limit = 30 is mentioned in storage class yaml and soft limit = 50 and soft grace period = 86400 are mentioned in PVC yaml . Then values set in quota will be advisory limit = 30, soft limit = 50 and soft grace period =86400.

Dynamic Logging Configuration

This feature is introduced in CSI Driver for PowerScale version 1.6.0 and updated in version 2.0.0

Helm based installation

As part of driver installation, a ConfigMap with the name isilon-config-params is created, which contains an attribute CSI_LOG_LEVEL which specifies the current log level of CSI driver.

Users can set the default log level by specifying log level to logLevel attribute in values.yaml during driver installation.

To change the log level dynamically to a different value user can edit the same values.yaml, and run the following command

cd dell-csi-helm-installer
./csi-install.sh --namespace isilon --values ./my-isilon-settings.yaml --upgrade

Note: here my-isilon-settings.yaml is a values.yaml file which user has used for driver installation.

Operator based installation

As part of driver installation, a ConfigMap with the name isilon-config-params is created using the manifest located in the sample file. This ConfigMap contains an attribute CSI_LOG_LEVEL which specifies the current log level of the CSI driver. To set the default/initial log level user can set this field during driver installation.

To update the log level dynamically user has to edit the ConfigMap isilon-config-params and update CSI_LOG_LEVEL to the desired log level.

kubectl edit configmap -n isilon isilon-config-params

Note: Prior to CSI Driver for PowerScale version 2.0.0, the log level was allowed to be updated dynamically through logLevel attribute in the secret object.

NAT Support

CSI Driver for Dell PowerScale is supported in the NAT environment.

Configurable permissions for volume directory

This feature is introduced in CSI Driver for PowerScale version 2.0.0

Helm based installation

The permissions for volume directory can now be configured in 3 ways:

  1. Through values.yaml
  2. Through secrets
  3. Through storage class
  # isiVolumePathPermissions: The permissions for isi volume directory path
  # This value acts as a default value for isiVolumePathPermissions, if not specified for a cluster config in secret
  # Allowed values: valid octal mode number
  # Default value: "0777"
  # Examples: "0777", "777", "0755"
  isiVolumePathPermissions: "0777"

The permissions present in values.yaml are the default for all cluster config.

If the volume permission is not present in storage class then secrets are considered and if it is not present even in secrets then values.yaml is considered.

Note:
For volume creation from source (volume from snapshot/volume from volume) permissions are inherited from source.

Create myvalues.yaml/my-isilon-settings.yaml and storage class accordingly.

Operator based installation

In the case of operator-based installation, default permission for powerscale directory is present in the samples file.

Other ways of configuring powerscale volume permissions remain the same as helm-based installation.

PV/PVC Metrics

CSI Driver for Dell PowerScale 2.1.0 and above supports volume health monitoring. This allows Kubernetes to report on the condition, status and usage of the underlying volumes. For example, if a volume were to be deleted from the array, or unmounted outside of Kubernetes, Kubernetes will now report these abnormal conditions as events.

This feature can be enabled

  1. Alpha feature gate CSIVolumeHealth needs to be enabled for the node side monitoring to take effect. For more information, please refer to the Kubernetes GitHub repository.
  2. For controller plugin, by setting attribute controller.healthMonitor.enabled to true in values.yaml file. Also health monitoring interval can be changed through attribute controller.healthMonitor.interval in values.yaml file.
  3. For node plugin, by setting attribute node.healthMonitor.enabled to true in values.yaml file.

Single Pod Access Mode for PersistentVolumes- ReadWriteOncePod

Use ReadWriteOncePod(RWOP) access mode if you want to ensure that only one pod across the whole cluster can read that PVC or write to it. This is supported for CSI Driver for PowerScale 2.1.0+ and Kubernetes version 1.22+.

Creating a PersistentVolumeClaim 

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: single-writer-only
spec:
  accessModes:
    - ReadWriteOncePod # the volume can be mounted as read-write by a single pod across the whole cluster
  resources:
    requests:
      storage: 1Gi

When this feature is enabled, the existing ReadWriteOnce(RWO) access mode restricts volume access to a single node and allows multiple pods on the same node to read from and write to the same volume.

To migrate existing PersistentVolumes to use ReadWriteOncePod, please follow the instruction from here.