This is unreleased documentation for SUSE® Storage 1.10 (Dev).

Volume Clone

Clone Using YAML

Clone a CSI Snapshot

To clone a CSI snapshot, refer to the documentation on Creating a Volume from a Snapshot.

Clone a Volume with the v2 Data Engine

Assume you have a StorageClass named longhorn-v2:

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: longhorn-v2
provisioner: driver.longhorn.io
allowVolumeExpansion: true
reclaimPolicy: Delete
volumeBindingMode: Immediate
parameters:
  dataEngine: "v2"
  numberOfReplicas: "1"
  staleReplicaTimeout: "2880"

And you have a PersistentVolumeClaim (PVC) named source-pvc-v2 provisioned from it:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: source-pvc-v2
spec:
  storageClassName: longhorn-v2
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi

Clone Using `full-copy` Mode

Create a new PVC with the same content as source-pvc-v2 by applying the following YAML. SUSE Storage will copy the data from the source PVC to the new PVC.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: cloned-pvc-v2
spec:
  storageClassName: longhorn-v2
  dataSource:
    name: source-pvc-v2
    kind: PersistentVolumeClaim
  accessModes:
    - ReadWriteOnce
  resources:
      requests:
        storage: 10Gi

Clone Using `linked-clone` Mode

The full-copy mode creates a new PVC that is fully independent of the source PVC. However, it requires time and resources to copy the data.

Sometimes, you need to quickly create a temporary PVC with the same content as the source without copying the data. For example, backup solutions like Velero or Kasten can use this feature to quickly create a temporary PVC to read data and upload it to an S3 bucket.

In this scenario, use the linked-clone mode. This mode creates a new PVC that shares the same data blocks as the source PVC.

Follow these steps:

Create a StorageClass with cloneMode set to linked-clone.

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: longhorn-v2-linked-clone
provisioner: driver.longhorn.io
reclaimPolicy: Delete
volumeBindingMode: Immediate
parameters:
  dataEngine: "v2"
  cloneMode: "linked-clone"
  numberOfReplicas: "1"
  staleReplicaTimeout: "2880"

Create a new PVC that uses the StorageClass you created and references the source PVC in the dataSource field.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: cloned-pvc-v2-linked-clone
spec:
  storageClassName: longhorn-v2-linked-clone
  dataSource:
    name: source-pvc-v2
    kind: PersistentVolumeClaim
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi

In addition to the the requirements for CSI Volume Cloning, the cloned PVC’s (cloned-pvc) resources.requests.storage must match the source PVC’s (source-pvc) storage size.
The linked-clone mode is only supported by the v2 data engine.
A PVC created using linked-clone shares data blocks with the source and has the following limitations:
- It can have only one replica.
- It cannot be snapshotted or backed up.
- It cannot be used as the source for another clone operation.
- A source PVC can only have one linked-clone PVC at a time.
- linked-clone PVCs are designed to be short-lived. We highly recommend you delete them when no longer needed.

For more examples of linked-clone mode, see the blog post: Backup Applications with Longhorn V2 Volumes using Velero.

Clone a Volume Using the SUSE Storage UI

You can also clone a v2 data engine volume using the SUSE Storage UI:

On the Volumes page, click Create Volume and select the data source (Volume or Volume Snapshot).
From the Volumes page, select a volume and click Clone Volume in the Operation menu.
On the Volumes page, select a volume, click its name, and in the Snapshot and Backups section, identify the snapshot you want to use, then click Clone Volume.
For bulk cloning, on the Volumes page, select one or more volumes and click the Clone Volume button at the top of the table.

History

Available since v1.10.0