A snapshot is the state of a Kubernetes volume at any given moment in time.

Snapshot Management via UI

To create a snapshot of an existing cluster, follow these steps:

1. In the top navigation bar of the Longhorn UI, click Volume.
2. Click the name of the volume for which you want to create a snapshot. This leads to the volume detail page.
3. Click the Take Snapshot button.

Once the snapshot is created, you will see it in the list of snapshots for the volume before the Volume Head.

Snapshot Management with Custom Resources (CRs)

This section demonstrates how to create, list, restore, and delete Longhorn snapshots directly via kubectl using Longhorn’s Custom Resources (CRs).

Note: Longhorn uses its own Snapshot CRD under the longhorn.io API group (for example, v1beta2), not the generic Kubernetes VolumeSnapshot from snapshot.storage.k8s.io.

Create a Snapshot

1. Prepare the manifest: Create a file named longhorn-snapshot.yaml:

   apiVersion: longhorn.io/v1beta2
   kind: Snapshot
   metadata:
     name: longhorn-test-snapshot
     namespace: longhorn-system
   spec:
     volume: pvc-840804d8-6f11-49fd-afae-54bc5be639de   # replace with your actual Longhorn volume name
     createSnapshot: true
   

2. Apply the manifest:

   kubectl apply -f longhorn-snapshot.yaml
   

   Expected output:

   snapshot.longhorn.io/longhorn-test-snapshot created
   

   Note: If the volume is detached, you will see a brief warning about the engine not running. Longhorn automatically retries, and the snapshot will complete once the volume is attached.

List Snapshots

kubectl get snapshots.longhorn.io -l longhornvolume=pvc-840804d8-6f11-49fd-afae-54bc5be639de -n longhorn-system

Delete a Snapshot

kubectl delete snapshot.longhorn.io longhorn-test-snapshot -n longhorn-system

Expected output:

snapshot.longhorn.io "longhorn-test-snapshot" deleted

Note: Longhorn automatically handles the cleanup of the underlying data.