Create a VolumeSnapshot

VolumeSnapshot creates a point-in-time snapshot of the independent fileset based IBM Storage Scale Container Storage Interface driver volume on the IBM Storage Scale storage system.

Create a VolumeSnapshotClass

VolumeSnapshotClass is like a StorageClass that defines driver-specific attributes for the snapshot to be created.

A sample VolumeSnapshotClass is created as shown in the following example:
# cat volumesnapshotclass.yaml
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshotClass
metadata:
  name: ibm-spectrum-scale-snapshot-class-consistency-group
driver: spectrumscale.csi.ibm.com
deletionPolicy: Delete
#parameters:
#        snapWindow: "30"
snapWindow parameter is valid for only consistency group. It indicates how long a snapshot stays valid for a consistency group after a snapshot is taken. The value specified should indicate snapWindow time in minutes. Default value is "30" minutes.
Note:
  • snapWindow must not be less than 30 minutes while taking snapshots of multiple volumes.
  • If there are multiple requests, only one snapshot for consistency group must be taken within the specified snapWindow.
  • snapWindow time starts when snapshot of any volume that belongs to the consistency group is taken either for the first time or any time after snapWindow is passed.
  • If one needs to take a snapshot of consistency group, request for snapshot for all volumes that belong to the consistency group must be created in a short span of time.

Create a VolumeSnapshot

VolumeSnapshot is a copy of a volume content on a storage system.

Specify the source volume to be used for creating snapshot here as shown in the following sample manifest. Source persistent volume claim (PVC) must be in the same namespace in which the snapshot is being created. Snapshots can be created only from independent fileset-based PVCs or for consistency group-based PVCs.

A sample VolumeSnapshot is created as shown in the following example:


# cat volumesnapshot.yaml
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: ibm-spectrum-scale-snapshot  
spec:
  volumeSnapshotClassName: ibm-spectrum-scale-snapshot-class
  source:
    persistentVolumeClaimName: ibm-spectrum-scale-pvc

Verify that snapshot is created

Use the following steps to ensure creation of volume snapshot.

Ensure that snapshot is in the READYTOUSE state and a corresponding file set snapshot must be available on IBM Storage Scale.
  • To get the status of volume snapshot, issue the following command.
    # kubectl get volumesnapshot
NAME    READYTOUSE   SOURCEPVC   SOURCESNAPSHOTCONTENT   RESTORESIZE   SNAPSHOTCLASS    SNAPSHOTCONTENT                                    CREATIONTIME   AGE
ibm-spectrum-scale-snapshot   true         ibm-spectrum-scale-pvc                            1Gi             ibm-spectrum-scale-snapshot-class       snapcontent-2b478910-28d1-4c29-8e12-556149095094   2d23h          2d23h
Note:
  • The volume size of the source PVC is used as the restore size of the snapshot. Any volume that is created from this snapshot must be of the same or larger capacity.
  • Volume Snapshot is supported only for the independent fileset based PVCs.