A virtual machine has two visible checkpoints, but its Virtual Hard Disks folder contains ten AVHDX files. When the VM is exported, only two AVHDX files appear in the export directory. Does that prove the remaining files are orphaned and safe to delete? Some checkpoints appear to have been created by a backup application and are listed as Recovery checkpoints. I'd like to verify the disk chain and clean this up safely before testing an import on another Hyper-V host.
2 Answers
Merge or otherwise consolidate the valid checkpoint chain before exporting. Backup software can leave stale or inconsistent checkpoints behind, and deleting AVHDX files manually can make the VM unbootable or destroy recent data. If the graphical tools won’t remove the Recovery checkpoints, investigate the backup software’s cleanup procedure and use carefully verified PowerShell operations. Work from a copy or test import first, and make sure you have a reliable backup and sufficient storage for the merge.
Not necessarily. The files left out of the export may still be part of a differencing-disk chain, so don’t delete them based only on the export contents. First identify the AVHDX currently assigned to the VM and inspect its parent chain. You can use PowerShell to review the VM’s disk assignments, or inspect the disk in Hyper-V Manager and repeatedly choose “Inspect Parent” until you reach the base VHDX. Also remember that checkpoint merges need enough free space—often at least as much as the largest AVHDX involved.
I couldn’t get the disk-assignment command to work, but Get-VMHardDiskDrive -VMName 'VM001' | Format-List showed one of the AVHDX files. Inspecting that file and following “Inspect Parent” revealed the expected differencing disks and base disk. The checkpoints appear to have been created by the backup agent and weren’t merged properly, so I’m going to verify the chain before changing anything.
That’s why I’m holding off on deleting anything. The GUI doesn’t offer a way to remove these checkpoints, so I’ll validate the parent relationships and test the cleanup on a separate Hyper-V host before touching production.