Volume Resize Failure Alert - Shrinking of volumes is not supported

PX Enterprise

Below alert is fired for one volume.

VOLUME    VolumeResizeFailed    35394596782481542                ALARM        1    Jan 6 07:22:37 UTC 2026    Jan 6 07:22:37 UTC 2026        Volume (Name: pvc-11cc52b4-08ae-4589-b2c5-59529997a872 Id: 35394596782481542) Resize failed with error: Shrinking of volumes is not supported. Current size for volume pvc-11cc52b4-08ae-4589-b2c5-59529997a872 is 107374182400, new size 69793218560

• This error occurs because the user is attempting to resize a PX volume to a value smaller than its current size. Since volume shrinking is not supported, Portworx correctly returns this error.
• PVC size reduction is not supported in Kubernetes. Resize requests are validated at the Kubernetes layer and forwarded to the CSI driver only if they are supported. Since Kubernetes blocks shrink operations, such requests should not reach the Portworx layer under normal conditions. Therefore, volume shrink–related errors are not expected from Portworx unless Kubernetes validation is bypassed.

This error can be expected only in the following scenario:

• A PVC is initially created with a defined size, and a corresponding backend PX volume is provisioned with the same size.
• At a later point, the backend PX volume is manually expanded to a larger size using the pxctl CLI. As a result, the PX volume size becomes larger than the PVC size recorded in Kubernetes.
• When the PVC size is subsequently updated to a value that is greater than the original PVC size but still smaller than the current PX volume size, Kubernetes validation allows the resize request to proceed.The request is then forwarded to the CSI driver and reaches the Portworx layer, where it fails because the operation effectively represents a volume shrink from the PX perspective. 
  • e.g: Example:
    If a PVC is initially created with a size of 50 GiB and the backend PX volume is manually expanded to 100 GiB, attempting to update the PVC size to 70 GiB will pass k8s validation but will be rejected by Portworx with a volume shrink–related error.

• Identify the size of the PX volume using below command

 pxctl volume inspect <PV name>

• Update PVC with exact same size or higher size