I had a situation when VM had 42 checkpoints after backup failure. I’ve tried the actions from my article Merge checkpoints (avhdx / vhdx), but it didn’t work, I had catastrofic failure error. That means the chain of snapshots (checkpoints) is broken.
Follow these steps to fix the issue:
- Turn off the VM and backup VM’s content
- Open Hyper-V Manager where is VM located. This will assures you have proper access permissions to the virtual disk
- Click on Edit disk, select the folder where VM keeps it’s vhdx
- Select very last check point file (with .avhdx extension)
- Select “Merge”
- You will be asked to confirm merge this file with the parent disk. The parent disk is a previous .avhdx file
- Do it until you have no avhdx files in VM’s folder. At the end you should have just single vhdx file
- Your VM will not run with this disk, because its only remember last avhdx file. Create new VM and copy vhdx file to there, attach it in VM’s hardware configuration.
- You will need to reconfigure network settings as well because your VM also get new vNIC.