Snapshot consolidation fails due to file locks held by Commvault backup proxy VM.

Products

• VMware vCenter Server 8.0

Issue/Introduction

•  Frequent vCenter Server alarms stating "Virtual machine disks consolidation is needed" for a specific virtual machine and snapshot consolidation tasks fail.
• Snapshot consolidation tasks fail with the error: Failed to lock the file (5).
• The vmware.log for the affected VM contains entries similar as:

YYYY-MM-DDTHH:mm:ss  In(05) vcpu-0 - ConsolidateEnd: Snapshot consolidate complete: Failed to lock the file (5).
YYYY-MM-DDTHH:mm:ss  In(05) vcpu-0 - SNAPSHOT: SnapshotFixDisksAfterCombineNative /vmfs/volumes/##/*.vmdk unlink fails with Failed to lock the file (16392)

• The VM configuration (.vmx) reveals an extensive snapshot chain (e.g., scsi0:0.fileName = "####-000316.vmdk").
• The VM is backed up using Commvault with snapshot-based backups.

Environment

VMware vCenter Server

Cause

This issue occurs when a Commvault backup proxy VM using HotAdd transport mode mounts the target VM's virtual disks but fails to unmount them after the backup job completes.

The proxy maintains an active lock on the base disk, which prevents the ESXi host from merging the snapshot chain.

Resolution

This issue is environmental and related to the third-party backup configuration (Commvault).

To resolve this issue, please engage your Commvault vendor to verify the Virtual Server Agent (VSA) proxy settings.

1. Review the configuration for the VSA Proxy VM.

2. Verify that the Auto-mount setting is disabled refer Choose how data is accessed (transport mode)

Additional Information

For further details on investigating file locks, see Investigating virtual machine file locks on ESXi hosts (314365)