Failing to start VM, snapshot not matching?

[mattig89ch]

Hello all,

So I just got this error when I tried to start my linux VM:

Code: Select all

Failed to start the virtual machine Linux Mint.

Parent UUID {00000000-0000-0000-0000-000000000000} of the medium 'C:\Users\Matt\VirtualBox VMs\Linux Mint\Snapshots/{79047eb1-c23b-41ca-9130-5ba5238a8216}.vhd' does not match UUID {03e2ec2b-4f92-4d4f-a142-58827ce0ff39} of its parent medium stored in the media registry ('C:\Users\Matt\.VirtualBox\VirtualBox.xml').

Result Code: E_FAIL (0x80004005)
Component: MediumWrap
Interface: IMedium {4afe423b-43e0-e9d0-82e8-ceb307940dda}

I don't actually know what to make of this. I did take a snapshot of this VM, as it was after my configuration was over. Then shut it down. But why is that no longer matching the VM?

[mpack]

It's quite straightforward, the "snapshot" is not a snapshot (that's what having a parent ID of 0000 means). I assume you cloned it for some reason (cloning merges a snapshot chain), then you replaced the original snapshot VDI with the clone.

It should be easy to copy the "snapshot" VDI to a new folder, rename it to something sensible, then create a new VM around it. You can't do that with actual differencing images btw, but your VDI is stand alone.

Make a backup of the VM folder before you do anything.

[mattig89ch]

I actually didn't duplicate it, that I know of. I got it running, hit the take snapshot button, and let it run.

[mpack]

I got it running, hit the take snapshot button, and let it run.

And that worked? That's surprising. It implies that the UUID linkage check is only performed on the current state.

It's still a kludge: you still have the wrong VDI in a snapshot chain, a landmine waiting to go off at some time in the future. If the VM is currently running that I suggest that you clone it (the VM, not just the disk). Keep current state only, don't reset the MAC. The cloned VM will be newly minted and free of landmines.