[Feature Request]: Online resizing of PVCs

[sauterp]

What feature would you like to have in the provider?

Unfortunately, due to limitations in the current Exoscale Block Storage design, the CSI cannot support online resizing. This means that to resize a volume, it would need to be detached from the Kubernetes node first. As a consequence, workloads that mount the volume will have to be stopped temporarily to detach the volume before resizing.

For the foreseeable future we cannot implement this feature but you are welcome to communicate your interest and need for this feature here through comments or reactions.

Thank you for understanding.

[wonko]

Some drivers allow the resize to happen, but then note that the pod should be cycled to allow the volume to expand. Here, it seems that the driver actually denies the resize if the volume is still in use. The former flow is much more user-friendly, as you can just resize the PVCs and then do a k rollout restart of whatever is using the volumes.

Also, the error is ugly:

│   Normal   ProvisioningSucceeded  9m42s                  csi.exoscale.com_exoscale-csi-controller-7578c45864-xrs77_f1b35fa8-11f4-4657-94e3-a3c2f327ec5f  Successfully provisioned volume pvc-e8d997d5-6b38-44ac-a113-08524cd35733        │
│   Warning  ExternalExpanding      11s                    volume_expand                                                                                   waiting for an external controller to expand this PVC                           │
│   Normal   Resizing               7s (x4 over 11s)       external-resizer csi.exoscale.com                                                               External resizer is resizing volume pvc-e8d997d5-6b38-44ac-a113-08524cd35733    │
│   Warning  VolumeResizeFailed     7s (x4 over 11s)       external-resizer csi.exoscale.com                                                               resize volume "pvc-e8d997d5-6b38-44ac-a113-08524cd35733" by resizer "csi.exosca │
│ le.com" failed: rpc error: code = Unknown desc = ResizeBlockStorageVolume: http response: invalid request: bad request

(i assume the "bad request" is the consequence of not having detached the volume).

[zifeo]

@sauterp Is there any update on this long awaited feature? Is there a downstream blocker or it's a matter of implementing the logic?

[pierre-emmanuelJ]

Hi @zifeo,

This is a direct limitation of our current Block Storage implementation. Online PVC resizing isn’t supported at the moment, and unfortunately there’s no ETA for when this will change.

That said, this capability will be included once our Block Storage v2 becomes available, but as of now, there’s no official release date for it.

Thanks for your understanding and patience.