The "used" storage value exceeds the limit set on the namespace after upgrading to vSphere 9.0

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

vSphere Client shows "used" value higher than the limit set on namespace.

Environment

vSphere 9.0 upgraded from 8.0 U3 or lower versions.

Cause

• The issue could occur when you upgrade vSphere to 9.0
• In 8.0 U3, the Storage Quota support was released. The storage quota in 9.0 took only volumes (PVC) into consideration for storage quota calculation. 
• The VolumeSnapshots on the PVC was not was not included into the storage quota calculations in 8.0 U3.
• When you upgrade to vSphere 9.0, it's possible that pre-existing snapshots from 8.0 U3 is now included into the storage quota.
• This now surfaces the snapshot space usage into the "used" storage space and it may lead to the situation that the "used" value goes beyond the limit.
• This could also happen when you have a mixed host Supervisor Cluster.
  
  For example:
  
  
  • A PVC could be attached to a Pod running on older hosts (8.0 U3) or lower
  • If any snapshot on PVCs, the snapshot usage is not returned since ESXi 9.0 host is required to get the snapshot usage.
  • You have upgraded the host to vSphere 9.0 which results in calculating the snapshot usage post upgrade and this increases the storage used.

Resolution

This is an expected behaviour after upgrading to vSphere 9.0, you may increase the limits to resolve this issue.