Error: "cannot get a LWD snapshot" when attempting to backup a VM using Power Protect Data Management

Products

• VMware vSphere ESXi

Issue/Introduction

• When trying to back up a VM using Power Protect Data Management, the task fails with an error:
  
  cannot get a LWD snapshot
  
  
• The 'disk in use' error in the dpd.log coincides with the time stamp of this event.
  
  
• ESXi - /var/log/dpd.log
  
  Date-Time.202Z In(166) dpd[75910224]: [Originator@6876 sub=Libs opID=4bf9a733-a734] WORKER: Creating new group with maxThreads=2 (4)
Date-Time.203Z In(166) dpd[75910224]: [Originator@6876 sub=Libs opID=4bf9a733-a734] LWD: CrossFD channel open at '47'
Date-Time.203Z In(166) dpd[75910224]: [Originator@6876 sub=Libs opID=4bf9a733-a734] LWD: Created a new AIO context 14CDC934C0. New pool size 1
Date-Time.204Z In(166) dpd[75910222]: [Originator@6876 sub=DiskInfo opID=4bf9a733-a734] Inserting disk b6e499ac-935e-df54-b08d-11f7156c8bc1 - /vmfs/volumes/[Datastore]/test.vmdk
Date-Time.204Z In(166) dpd[75910224]: [Originator@6876 sub=Libs opID=4bf9a733-a734] LWD: Opened disk 14CC00C570
Date-Time.208Z In(166) dpd[75910224]: [Originator@6876 sub=DiskLib opID=4bf9a733-a734] DISKLIB-CTK   : Could not open change tracking file "/vmfs/volumes/[Datastore]/test-ctk.vmdk": Change tracking invalid or disk in use.
Date-Time.449Z In(166) dpd[75910343]: [Originator@6876 sub=Default] SplDiskUnstun: called with handle 14CC00CE30
Date-Time.449Z In(166) dpd[75910201]: -->

Environment

vSphere 8.x

Cause

The issue occurs as a result of a stuck backup process due to ctk errors whereby the vmdk file is not cleared.

Resolution

At this time, there is no resolution.

Workaround

1. Create a new temporary directory in the vm folder.
2. Move the ctk and the vmsd files to the temporary directory created in the step 1.
3. Restart the vm.
4. Re-attempt to back up the vm.

Additional Information

"Operation failed Failed to start the virtual machine. Cannot open the disk" while powering on a virtual machine