VAST Block CSI Driver Workflow

  • Updated on Jan 30, 2026
  • Published on Jan 26, 2026
  • 3 minute(s) read
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To let your applications use block storage on a VAST cluster, define a Kubernetes storage class for block storage and reference it in the PVC. Based on the storage class definition, VAST Block CSI Driver will provision a block volume for the PVC using a preconfigured view on the VAST cluster.

  1. Ensure that the following prerequisites are met:

  2. Add a storage class that will be used to provision block volumes. In the storage class definition:

    • Specify the block.csi.vastdata.com provisioner.

    • Add the subsystem parameter to specify the name of the NVMe subsystem where block volumes will be created. This NVMe subsystem must be associated with a VAST cluster view  preconfigured for block storage. If the VAST cluster exposes multiple subsystems that share the same name across VAST tenants, specify the tenantName option to for the driver to pick the subsystem associated with the tenant you need.

    • Optionally, define volume naming using the volumeGroup parameter.

    • Ensure that the virtual IP pool belongs to the same tenant as the VAST cluster's view configured for block storage provisioning.

    Tip

    For more detailed guidelines, see  Creating Block Storage Classes. For more examples, see https://github.com/vast-data/vast-csi/tree/v2.6/examples/block.

    For example:

    apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: vastdata-filesystem
parameters:
  csi.storage.k8s.io/controller-expand-secret-name: vast-mgmt
  csi.storage.k8s.io/controller-expand-secret-namespace: default
  csi.storage.k8s.io/controller-publish-secret-name: vast-mgmt
  csi.storage.k8s.io/controller-publish-secret-namespace: default
  csi.storage.k8s.io/node-publish-secret-name: vast-mgmt
  csi.storage.k8s.io/node-publish-secret-namespace: default
  csi.storage.k8s.io/node-stage-secret-name: vast-mgmt
  csi.storage.k8s.io/node-stage-secret-namespace: default
  csi.storage.k8s.io/provisioner-secret-name: vast-mgmt
  csi.storage.k8s.io/provisioner-secret-namespace: default
  fsType: xfs
  subsystem: BlockView
  vip_pool_fqdn: 'MyDomain'
  volume_group: folder1/folder2/block-{namespace}-{id}
provisioner: block.csi.vastdata.com
reclaimPolicy: Delete
volumeBindingMode: Immediate
allowVolumeExpansion: true

  3. Create a Persistent Volume Claim (PVC) as follows:

    • Specify the volumeMode as  Block for raw block storage or FileSystem (default) for formatted volumes. For more information on volume modes, see Volume Modes.

    • Reference the newly created block storage class in storageClassName.

    For example:

    kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pvc-raw-block
spec:
 volumeMode: Block 
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
 storageClassName: vast-block-sc

  4. Reference the newly created PVC on the claimName parameter in the pod definition.

    For example:

    apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
    - name: app-container
      image: nginx
      volumeMounts:
        - name: data
          mountPath: /mnt/data
  volumes:
    - name: data
      persistentVolumeClaim:
        claimName: pvc-raw-block

VAST Cluster Requirements and Preconfigurations

VAST Cluster 5.3 or later is required to provision block volumes.

The VAST cluster must be configured for block storage provisioning as follows:

  • Block storage support is enabled for the tenant where block volumes will be created.

  • Under the tenant, there exists a view that exposes the NVMe subsystem where block volumes will be created. The view must have the block storage protocol enabled and the NVMe subsystem defined.

    Note

    Note that the block storage view is not automatically created by VAST Block CSI Driver. It must be created manually beforehand.

Kubernetes Requirements

  • A host connecting to block storage must have an NVMe driver installed and configured as needed. This is done outside of VAST Block CSI Driver.

  • The nvme-cli package must be installed on Kubernetes nodes where volumes are to be created.

Volume Modes

VAST Block CSI Driver supports the following volume modes, which can be specified using the volumeMode option in the PVC definition:

  • Block: A volume is presented to the pod as a raw block device without any filesystem on it.

    Ephemeral volumes cannot be provisioned in this mode.

  • Filesystem (default): A volume is formatted using the filesystem type specified in the storage class definition. The following filesystem types are supported: ext4 (default), ext3 and xfs.

    In this mode, the volume can be attached to multiple pods simultaneously, but all pods must be scheduled on the same node.

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