Tenant Storage Quota Increases Unexpectedly During Snapshot Operations in VCD 10.6.x

Products

• VMware Cloud Director

Issue/Introduction

• Taking a snapshot on vCenter for a VM managed by Cloud Director can reduce the available storage allocation in the associated Org VDC.
• This document outlines the behavior observed in VMware Cloud Director 10.6 where taking a snapshot of a Cloud Director-managed VMs results in the snapshot size being deducted from the Org VDC's storage allocation. While this behavior is by design in version 10.6, it has led to unexpected storage consumption, especially when temporary snapshots are created by backup solutions. This document details the cause, justification, and the change in behavior going forward. 
• Also after upgrading to VMware Cloud Director version 10.6.1.1, the issue related to tenant storage consumption during VM snapshots—primarily triggered by Veeam Backup operations—still persists.
• Although the problem was identified in version 10.6.1 and was marked as resolved in the 10.6.1.1 release notes, it continues to occur.

• During the backup process, snapshots are created and removed as expected; however, tenant storage usage increases while the snapshot exists and only decreases after it is deleted.
• This behavior is new to version 10.6.1 and was not observed in earlier versions, where snapshots created by backups did not affect the tenant's allocated storage. 

Environment

 VMware Cloud Director 10.6.1

 VMware Cloud Director 10.6.1.1

Cause

Starting with VMware Cloud Director 10.6, a design change was introduced where Cloud Director actively synchronizes snapshot data from the underlying vCenter. As part of this enhancement, Cloud Director now calculates storage usage—including snapshots—based on data retrieved via the vCenter Snapshot API.

 

As a result of this change, the storage consumed by snapshots, including those created temporarily by backup solutions, is counted against the Org VDC’s allocated storage. This behavior leads to a reduction in the reported available storage, even if the snapshots are short-lived or managed externally. While this is functioning as intended in version 10.6, it has led to unexpected storage accounting outcomes for end users.

Resolution

A change in the storage allocation logic has been implemented in the VMware Cloud Director 10.6.1.1 release.  This update refines how snapshot storage is accounted for, ensuring that temporary snapshots — such as those created by backup solutions — do not incorrectly consume the Org VDC's allocated storage.

 

To implement this feature:

1. Upgrade to Cloud Director version 10.6.1.1.
2. Once Cloud Director is upgraded and running; ssh as root to one of the cells.
3. Run the following Cell Management Tool command to enable the feature:

/opt/vmware/vcloud-director/bin/cell-management-tool manage-config -n vm.hideExternalSnapshots -v true

     4. Check that the feature is now enabled:

/opt/vmware/vcloud-director/bin/cell-management-tool manage-config -n vm.hideExternalSnapshots -l

 

Note: After applying the resolution above VMware Cloud Director will still be aware of external snapshots on the vCenter level, non admin users will not see any external snapshots on the VM's however admin users will still see the external snapshots. Cloud Director will also still take into account any snapshots taken in vCenter when calculating if the organization snapshot limit has been reached.

Additional Information

Additional details -

You manage this property using the cell-management-tool, which is found on each VCD cell (typically under /opt/vmware/vcloud-director/bin/):

To Set the Property:

/opt/vmware/vcloud-director/bin/cell-management-tool manage-config -n vm.hideExternalSnapshots -v true

 

To View Current Value:

/opt/vmware/vcloud-director/bin/cell-management-tool manage-config -n vm.hideExternalSnapshots -l

 

To Revert (if needed):

/opt/vmware/vcloud-director/bin/cell-management-tool manage-config -n vm.hideExternalSnapshots -v false