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

Volume Expansion

Starting with v1.10.0, SUSE Storage supports online expansion for v2 data engine volumes that use the NVMe frontend. This feature allows you to expand a volume to the requested size while keeping the workload running.

During the expansion process, SUSE Storage automatically resizes all replicas to match the user-requested size. This eliminates the need to stop or detach the application from the volume, ensuring a seamless and non-disruptive scaling of storage.

This capability significantly improves storage management flexibility in storage management by enabling volumes to be scaled without any downtime.

How to use

When creating the V2 volume from the SUSE Storage UI

Select a volume with Block Device or NVMf as the frontend.
In the SUSE Storage UI, navigate to the Volumes page.
Click Expand Volume from the volume operations menu.
Enter the new desired size and confirm. The expansion will begin automatically.

When creating the v2 volume from manifest

Create a StorageClass for the v2 data engine. Make sure allowVolumeExpansion is set to true. For example:

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
    name: longhorn-v2-data-engine
provisioner: driver.longhorn.io
allowVolumeExpansion: true
reclaimPolicy: Delete
volumeBindingMode: Immediate
parameters:
  numberOfReplicas: "3"
  staleReplicaTimeout: "2880"
  fsType: "ext4"
  dataEngine: "v2"

Create a PersistentVolumeClaim (PVC) that references this StorageClass:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: longhorn-volv-pvc
  namespace: default
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: longhorn-v2-data-engine
  resources:
    requests:
      storage: 2Gi

To expand the volume, edit the PVC manifest to increase the storage request to a larger size (shown below), then apply the updated manifest.
```
  resources:
    requests:
      storage: 3Gi
```

Known Limitations

The UBLK frontend does not support online expansion as of v1.10.0. You are not allowed to expand a volume that uses the UBLK frontend.

Reference

For more information, see Issue #8022.