Using snapshots

The yaook/k8s cluster provides the functionality of creating snapshots of your PVCs in Openstack.

Creating snapshot

The yk8s LCM provides besides the default storage-class csi-sc-cinderplugin a default volume-snapshot-class csi-cinder-snapclass. To create a snapshot for a PVC apply the following yaml (make changes accordingly). You can create your own VolumeSnapshotClass, see managed-k8s/k8s-base/roles/connect-k8s-to-openstack/files/cinder/volume_snapshot_storag_class.yaml for details.

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: <name-of-snapshot>
  namespace: <namespace>
spec:
  volumeSnapshotClassName: csi-cinder-snapclass
  source:
    persistentVolumeClaimName: <name-of-PVC>

Rehydrating snapshot

To rehydrate a previous snapshot apply the following yaml (make changes accordingly)

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: <name-of-restore-pvc>
namespace: <namespace>
spec:
storageClassName: csi-sc-cinderplugin
dataSource:
  name: <name-of-snapshot>
  kind: VolumeSnapshot
  apiGroup: snapshot.storage.k8s.io
accessModes:
  - ReadWriteOnce
resources:
  requests:
    storage: 2Gi

Deleting snapshot

When deleting snapshots make sure to first remove any rehydration of it. To remove a PV, snapshots created from it also need to be removed before. k8s doesn’t exit with an error or warning if a deletion wasn’t successful. Also kubectl get volumesnapshots -A may output no snapshots, but openstack volume snapshot list will.