Steps to migrate snapshot migration after migrating cstor volumes to CSI spec.

Snapshot-Migration.md

1. Make sure the volume migration is successful. Follow the volume migration steps from the docs.

2. Get the yamls for old volumesnapshot and volumesnapshotdata.

   • List old volumesnapshots and

   mayadata:cstor$ kubectl get volumesnapshots.volumesnapshot.external-storage.k8s.io
   NAME                  AGE
   snapshot-demo-cstor   7s

   • Select the snapshot to migrate and get the -o yaml output.

   mayadata:cstor$ kubectl get volumesnapshots.volumesnapshot.external-storage.k8s.io snapshot-demo-cstor -oyaml
   apiVersion: volumesnapshot.external-storage.k8s.io/v1
   kind: VolumeSnapshot
   metadata:
     annotations:
       kubectl.kubernetes.io/last-applied-configuration: |
         {"apiVersion":"volumesnapshot.external-storage.k8s.io/v1","kind":"VolumeSnapshot","metadata":{"annotations":{},"name":"snapshot-demo-cstor","namespace":"default"},"spec":{"persistentVolumeClaimName":"demo-vol-claim-1"}}
     creationTimestamp: "2020-06-12T05:06:30Z"
     generation: 3
     labels:
       SnapshotMetadata-PVName: pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a
       SnapshotMetadata-Timestamp: "1591938390389915555"
     name: snapshot-demo-cstor
     namespace: default
     resourceVersion: "1356"
     selfLink: /apis/volumesnapshot.external-storage.k8s.io/v1/namespaces/default/volumesnapshots/snapshot-demo-cstor
     uid: 51cc8860-a5b6-473f-8d96-8ca8fa90f4ad
   spec:
     persistentVolumeClaimName: demo-vol-claim-1
     snapshotDataName: k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
   status:
     conditions:
     - lastTransitionTime: "2020-06-12T05:06:31Z"
       message: Snapshot created successfully
       reason: ""
       status: "True"
       type: Ready
     creationTimestamp: null

   • Get the snapshotDataName from the output of previous step and get -o yaml for corresponding volumesnapshotdata.

   mayadata:cstor$ kubectl get volumesnapshotdatas.volumesnapshot.external-storage.k8s.io k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005 -oyaml
   apiVersion: volumesnapshot.external-storage.k8s.io/v1
   kind: VolumeSnapshotData
   metadata:
     creationTimestamp: "2020-06-12T05:06:31Z"
     generation: 1
     name: k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
     resourceVersion: "1355"
     selfLink: /apis/volumesnapshot.external-storage.k8s.io/v1/volumesnapshotdatas/k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
     uid: 7fb73143-5da2-4ff4-9eb8-aaf98060328e
   spec:
     openebsVolume:
       capacity: 5Gi
       snapshotId: pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a_snapshot-demo-cstor_1591938390393273386
     persistentVolumeRef:
       kind: PersistentVolume
       name: pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a
     volumeSnapshotRef:
       kind: VolumeSnapshot
       name: default/snapshot-demo-cstor-51cc8860-a5b6-473f-8d96-8ca8fa90f4ad
   status:
     conditions:
     - lastTransitionTime: "2020-06-12T05:06:31Z"
       message: Snapshot created successfully
       reason: ""
       status: "True"
       type: Ready
     creationTimestamp: null

3. Make sure the volumesnapshotclass csi-cstor-snapshotclass is present

   mayadata:cstor-csi$ kubectl get volumesnapshotclasses.snapshot.storage.k8s.io 
   NAME                      AGE
   csi-cstor-snapshotclass   2m17s

   If not you can use the below command.

   mayadata:cstor-csi$ kubectl apply -f https://raw.githubusercontent.com/openebs/cstor-csi/master/deploy/snapshot-class.yaml

4. Create volumesnapshotcontent for the corresponding volumesnapshotdata. Get the persistentVolumeRef name and openebsVolume snapshotId from the old volumesnapshot data. For example the above volumesnapshotdata has persistentVolumeRef name as pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a and openebsVolume snapshotId as pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a_snapshot-demo-cstor_1591938390393273386. Now we will populate the below yaml according to the comments in the yaml.

   apiVersion: snapshot.storage.k8s.io/v1beta1
    kind: VolumeSnapshotContent
    metadata:
      # the name should be same the old volumesnapshotdata
      name: k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
    spec:
      deletionPolicy: Delete
      driver: cstor.csi.openebs.io
      source:
        # the snapshotHandle should be <persistentVolumeRef name>@<openebsVolume snapshotId>
        snapshotHandle: pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a@pvc-dd6ad226-c2b3-47c8-a8bf-46cb820d187a_snapshot-demo-cstor_1591938390393273386
      volumeSnapshotClassName: csi-cstor-snapshotclass
      volumeSnapshotRef:
        apiVersion: snapshot.storage.k8s.io/v1beta1
        kind: VolumeSnapshot
        # the name of should be same as old volumesnapshot
        name: snapshot-demo-cstor
        namespace: default

   Apply the above yaml after properly configuring it.

5. Create new volumesnapshot for the corresponding old volumesnapshot. Configure the below yaml according to comments and apply it.

   apiVersion: snapshot.storage.k8s.io/v1beta1
   kind: VolumeSnapshot
   metadata:
     name: snapshot-demo-cstor
     namespace: default
   spec:
     source:
       # the volumeSnapshotContentName should be same as the name of the one created in above step. 
       volumeSnapshotContentName: k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
     volumeSnapshotClassName: csi-cstor-snapshotclass

   This should bind both the volumesnapshotcontent and new volumesnapshot together.

6. Verify that the new snapshot is bound.

   mayadata:setup$ kubectl get volumesnapshots.snapshot.storage.k8s.io snapshot-demo-cstor -oyaml          
   apiVersion: snapshot.storage.k8s.io/v1beta1
   kind: VolumeSnapshot
   metadata:
     annotations:
       kubectl.kubernetes.io/last-applied-configuration: |
         {"apiVersion":"snapshot.storage.k8s.io/v1beta1","kind":"VolumeSnapshot","metadata":{"annotations":{},"name":"snapshot-demo-cstor","namespace":"default"},"spec":{"source":{"volumeSnapshotContentName":"k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005"},"volumeSnapshotClassName":"csi-cstor-snapshotclass"}}
     creationTimestamp: "2020-06-12T05:50:42Z"
     finalizers:
     - snapshot.storage.kubernetes.io/volumesnapshot-as-source-protection
     - snapshot.storage.kubernetes.io/volumesnapshot-bound-protection
     generation: 1
     name: snapshot-demo-cstor
     namespace: default
     resourceVersion: "7065"
     selfLink: /apis/snapshot.storage.k8s.io/v1beta1/namespaces/default/volumesnapshots/snapshot-demo-cstor
     uid: 382e5bec-c4f5-4dd8-a4f8-2c02a70391c1
   spec:
     source:
       volumeSnapshotContentName: k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
     volumeSnapshotClassName: csi-cstor-snapshotclass
   status:
     boundVolumeSnapshotContentName: k8s-volume-snapshot-7ad32bd7-ac6a-11ea-8edf-0242ac110005
     creationTime: "2020-06-12T05:50:35Z"
     readyToUse: true
     restoreSize: "0"

7. Delete the old volume snapshot.

   mayadata:setup$ kubectl delete volumesnapshots.volumesnapshot.external-storage.k8s.io snapshot-demo-cstor 
   volumesnapshot.volumesnapshot.external-storage.k8s.io "snapshot-demo-cstor" deleted