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volume expansion¶

HwameiStor supports CSI volume expansion. This function implements online volume expansion by modifying the size of PVC.

In the example below, we expand the PVC data-sts-mysql-local-0 from 1GiB to 2GiB.

Current PVC/PV size:

$ kubectl get pvc data-sts-mysql-local-0
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGE CLASS AGE
data-sts-mysql-local-0 Bound pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8 1Gi RWO hwameistor-storage-lvm-hdd 85m

$ kubectl get pv pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGE CLASS REASON AGE
pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8 1Gi RWO Delete Bound default/data-sts-mysql-local-0 hwameistor-storage-lvm-hdd 85m

Check whether `StorageClass` uses the parameter `allowVolumeExpansion: true`¶

$ kubectl get pvc data-sts-mysql-local-0 -o jsonpath='{.spec.storageClassName}'
hwameistor-storage-lvm-hdd

$ kubectl get sc hwameistor-storage-lvm-hdd -o jsonpath='{.allowVolumeExpansion}'
true

Modify the size of `PVC`¶

$ kubectl get edit pvc data-sts-mysql-local-0

...
spec:
  resources:
    requests:
      storage: 2Gi
...

Observe the expansion process¶

The more capacity you add, the longer it will take to expand. You can observe the entire expansion process in the event log of PVC.

$ kubectl describe pvc data-sts-mysql-local-0

Events:
  Type Reason Age From Message
  ---- ------- ---- ---- -------
  Warning ExternalExpanding 34s volume_expand Ignoring the PVC: didn't find a plugin capable of expanding the volume; waiting for an external controller to process this PVC.
  Warning VolumeResizeFailed 33s external-resizer lvm.hwameistor.io resize volume "pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8" by resizer "lvm.hwameistor.io" failed: rpc error: me code = unsionknown comp descan = ed vo
  Normal Resizing 32s (x2 over 33s) external-resizer lvm.hwameistor.io External resizer is resizing volume pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8
  Normal FileSystemResizeRequired 32s external-resizer lvm.hwameistor.io Require file system resize of volume on node
  Normal FileSystemResizeSuccessful 11s kubelet MountVolume.NodeExpandVolume succeeded for volume "pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8" k8s-worker-3

Observe the `PVC/PV` after the expansion is completed¶

$ kubectl get pvc data-sts-mysql-local-0
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGE CLASS AGE
data-sts-mysql-local-0 Bound pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8 2Gi RWO hwameistor-storage-lvm-hdd 96m

$ kubectl get pv pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGE CLASS REASON AGE
pvc-b9fc8651-97b8-414c-8bcf-c8d2708c4ee8 2Gi RWO Delete Bound default/data-sts-mysql-local-0 hwameistor-storage-lvm-hdd 96m

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