Trying to delete a snapshot on my VM to free up some space I got this error:
Failed to delete the snapshot XXXX of the virtual machine YYYY
Hard disk ‘ZZZZ’ has more than one child hard disk (2).
Fortunately I found an easy solution here on Nicholas Jolet’s blog, repeated below:
In the snapshot manager, there were only two snapshots linked to my virtual machine.
I could delete the newest one, but I was not able to delete the oldest one/root snapshot.
To resolve this issue, I went to the “File > Virtual Media Manager” menu, then the [Hard Disks] tab and I’ve expanded the tree under my virtual machine.
I’ve deleted one snapshot that was not linked to any virtual machine, or snapshot.
After what I was able to delete my oldest/root snapshot.
And it worked perfectly!