Good evening, all!
Coming back to the question of orphaned snapshots -
My customer has a Window server 2003 VM (yep, was updated, only there for archival purposes) running in a Windows 2012 R2 Hyper-V cluster. I tried to migrate this VM to a new 2019 Hyper-V host; migration failed immediately at the source, throwing Error 21024 - the migration failed.
On closer examination I found that the VM had .avhd and .avhdx disks running, with links to the parent disks. In Hyper-V Manager, there are no checkpoints listed, but I can't edit the disk because the snapshots exist. I've seen conflicting information on fixing this - shut down the VM and it'll cure itself, manual merging the snapshots to the parent disk, exporting the VM, use PowerShell instead of Hyper-V Manager, and other more exotic fixes. I shut down the VM and left it for several hours; the disk sizes didn't change. I copied the existing file structures to another location so they wouldn't be lost as I worked on the existing disks.
So there are three issues here:
1. Is this likely the reason the migration is failing, or do I need to look further for why the migration failed?
2. What's the least risky method to merge these and restore the disk structure to something closer to normal? I'm from a VMware background, so some of the quick fixes will need references.
3. Is there a way to test this using the disk files I copied over to the offline location? Is there more documentation on how VHDx formats work so I can reasonably predict the outcome of one recovery method over another?
Thanks to all for looking!
G