Snapshots

Volume Snapshot Feature

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

• Kubernetes Volume Snapshot CRDs
• Volume Snapshot Controller
• Volume Snapshot Class

Note: From v1.7, the CSI driver installation process will no longer create VolumeSnapshotClass. If you want to create VolumeSnapshots, then create a VolumeSnapshotClass using the sample provided in the /samples/volumesnapshotclass folder under respective drivers.

Creating Volume Snapshots

The following is a sample manifest for creating a Volume Snapshot using the v1 snapshot APIs:

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: pvol0-snap1
spec:
  volumeSnapshotClassName: csm-snapclass
  source:
    persistentVolumeClaimName: pvol0

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

Note: VolumeSnapshots can be listed using the command kubectl get volumesnapshot -n <namespace>

(Optional) Volume Snapshot Requirements

Applicable only if you decide to enable the snapshot feature in values.yaml.

snapshot:
  enabled: true

Volume Snapshot CRD’s

The Kubernetes Volume Snapshot CRDs can be obtained and installed from the external-snapshotter project on Github. For installation, use v8.1.x

Volume Snapshot Controller

The CSI external-snapshotter sidecar is split into two controllers to support Volume snapshots.

• A common snapshot controller
• A CSI external-snapshotter sidecar

The common snapshot controller must be installed only once in the cluster, irrespective of the number of CSI drivers installed in the cluster. On OpenShift clusters 4.4 and later, the common snapshot-controller is pre-installed. In the clusters where it is not present, it can be installed using kubectl and the manifests are available here: v8.1.x

NOTE:

• The manifests available on GitHub install the snapshotter image: quay.io/k8scsi/csi-snapshotter:v4.0.x
• The CSI external-snapshotter sidecar is still installed along with the driver and does not involve any extra configuration.

Installation example

You can install CRDs and the default snapshot controller by running the following commands:

git clone https://github.com/kubernetes-csi/external-snapshotter/
cd ./external-snapshotter
git checkout v8.1.0
kubectl kustomize client/config/crd | kubectl create -f -
kubectl -n kube-system kustomize deploy/kubernetes/snapshot-controller | kubectl create -f -

NOTE:

• It is recommended to use the 8.1.x version of snapshotter/snapshot-controller.
• The CSI external-snapshotter sidecar is still installed along with the driver and does not involve any extra configuration.