Cannot take snapshot of virtual machine with error: An error occurred while saving the snapshot: msg.changetracker.MIRRORCOPYSTATUS.

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

Unable to take snapshot of a specific VM and the UI shows the error as below:

An error occurred while saving the snapshot: msg.changetracker.MIRRORCOPYSTATUS. An error occurred while taking a snapshot: msg.changetracker.MIRRORCOPYSTATUS.

The same error would show up when we try cloning the VM.

Environment

VMware vSphere 7.x

VMware vSphere 8.x

Cause

The snapshot failure is caused by file lock and mirror status for CTK file with events 'Failed to copy mirror: Lost previously held disk lock'. It is due to Stale CBT state (Eg: after restore) if stale CBT persisted or Backup tool timing issue while taking snapshot and consolidation processes. 

Virtual machine logs (vmware.log) show the events as below.

vmware.log for the virtual machine (/vmfs/volumes/datastore/vm-name/vmware.log)

2025-05-05T15:00:15.670Z Wa(03) vmx - DISKLIB-CBT   : ChangeTrackerESX_GetMirrorCopyProgress: Failed to copy mirror: Lost previously held disk lock
2025-05-05T15:00:15.670Z In(05) vmx - DISKLIB-LIB_BLOCKTRACK   : DiskLibBlockTrackMirrorProgress: Failed to get mirror status of block track info file /vmfs/volumes/vsan:######-545b21d#######/#####-99df-1c4e-#####/###.tr-####.r###_1-###.vmdk.
2025-05-05T15:00:15.670Z In(05) vmx - DISKLIB-CBT   : ChangeTrackerESX_DestroyMirror: Destroyed mirror node 5###-26#####c-cbtmirror. SrcFd: /vmfs/volumes/vsan:######-545b21#######/#####-5eb0-99df-1c4e-######/te@####n.tr-####.####_1-#####.vmdk, DestFd: /vmfs/volumes/vsan:#####-######7b57/######-####-#####/####.tr#####
2025-05-05T15:00:15.678Z In(05) vmx - SNAPSHOT: SnapshotPrepareTakeDoneCB: Failed to prepare block track.
2025-05-05T15:00:15.687Z Wa(03) vmx - DISKLIB-CBT   : ChangeTrackerESX_GetMirrorCopyProgress: Failed to copy mirror: Lost previously held disk lock

ESXi hostd logs (/var/log/hostd.log) show the events as below.

2025-05-05T15:00:15.532Z In(166) Hostd[2102996]: [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/vsan:5284a75########-#####/#######-5eb0-###-1c4e-#####/###.###-####.###.vmx opID=###-c5-4f9d sid=52b8626f user=vpxuser:VSPHERE.LOCAL\###] State Transition (VM_STATE_ON -> VM_STATE_CREATE_SNAPSHOT)
2025-05-05T15:00:15.697Z Db(167) Hostd[2103013]: [Originator@6876 sub=Vigor.Vmsvc.vm:/vmfs/volumes/vsan:#####-545b21db########/#####-5eb0-99df-1c4e-######/####.tr-###.####.vmx] Create Snapshot message: An error occurred while saving the snapshot: Could not get mirror copy status.
2025-05-05T15:00:15.697Z Db(167) Hostd[2102992]: --> An error occurred while taking a snapshot: Could not get mirror copy status.

Resolution

Migrate the Virtual Machine to another host and then snapshot creation should happen without issues.

Creation and deletion of snapshots will work as expected after the migration.