AKS Backup Issue with File CSI PVC

Question

Hello everyone,

I am currently migrating backups in our AKS cluster from Velero to AKS Backup, but I am encountering issues with restoring file CSI PVCs.

I attempted to restore a deleted file PVC, but the process failed, the PVC remained in a pending state for over an hour. In the Azure portal, I can see that a new file share was created, but the corresponding PV was not provisioned.

When I run kubectl describe pvc, I receive the following errors:

$ kubectl describe pvc test-statefulset1-0 -n test-file-pv
Name:          test-statefulset1-0
Namespace:     test-file-pv
StorageClass:  azurefile-csi
Status:        Pending
Volume:        
Labels:        velero.io/backup-name=bkp.a433a4bd-a57d-4c8b-b4ab-a9cb44493074.202503211238177408691
               velero.io/restore-name=res.a433a4bd-a57d-4c8b-b4ab-a9cb444930e7.202503211253552070187
               velero.io/volume-snapshot-name=velero-test-statefulset1-0-vdg89
Annotations:   backup.velero.io/must-include-additional-items: true
               volume.beta.kubernetes.io/storage-provisioner: file.csi.azure.com
               volume.kubernetes.io/storage-provisioner: file.csi.azure.com
Finalizers:    [kubernetes.io/pvc-protection]
Capacity:      
Access Modes:  
VolumeMode:    Filesystem
DataSource:
  APIGroup:  snapshot.storage.k8s.io
  Kind:      VolumeSnapshot
  Name:      velero-test-statefulset1-0-vdg89
Used By:     statefulset1-0
Events:
  Type     Reason                Age                    From                                                                                               Message
  ----     ------                ----                   ----                                                                                               -------
  Warning  ProvisioningFailed    20m (x14 over 42m)     file.csi.azure.com_csi-azurefile-controller-7d96574d59-6w7m8_c26e6611-9cbc-4b57-86ed-fb08c7f59ae6  failed to provision volume with StorageClass "azurefile-csi": rpc error: code = InvalidArgument desc = copy volume from volumeSnapshot is not supported
  Normal   Provisioning          5m38s (x18 over 42m)   file.csi.azure.com_csi-azurefile-controller-7d96574d59-6w7m8_c26e6611-9cbc-4b57-86ed-fb08c7f59ae6  External provisioner is provisioning volume for claim "test-file-pv/test-statefulset1-0"
  Normal   ExternalProvisioning  2m42s (x163 over 42m)  persistentvolume-controller                                                                        waiting for a volume to be created, either by external provisioner "file.csi.azure.com" or manually created by system administrator

Could someone help troubleshoot this issue?
Thanks a lot!

Answer 1

Hello Fatma •

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

I understand that you are experiencing issues when trying to restore snapshots from your AKS backup of Azure File CSI.

As per the note here https://learn.microsoft.com/en-us/azure/backup/azure-kubernetes-service-backup-overview the issue you are facing is expected as the operation are not supported.

Below you can find more details :

https://learn.microsoft.com/en-us/azure/backup/azure-kubernetes-service-cluster-backup-support-matrix#limitations

Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

If you have any other questions or are still running into more issues, let me know in the "comments" and I would be happy to help you.

Thank You.

Lisboa