Earlier today I had a running virtual machine, with an old snap0 snapshot from when it was set up. I took a second snapshot and upgraded a whole load of packages on the VM. This broke some customisations and so I needed to roll back, but I wanted to keep a copy of the upgraded VM alongside so I could compare. I had at this point also taken a newer snapshot of the same VM.
I copied the VM to a new instance, changed its IP address (we’re using static IPs on our VMs) and it fired up fine. Then I attempted to rollback to my earlier (good) snapshot from today on the original VM. I encountered the “ZFS won’t let you do that” error widely reported here, so I deleted my most recent snapshot and tried again. This appears to work on the console, but gives me the most recent state when I start it up, and not the “last known good” state which was the whole point of the snapshot!
What am I doing wrong? Or does the ZFS issue in fact mean that even deleting subsequent snapshots won’t let me roll back? That can’t be right surely, or there’s no point in having multiple snapshot capability at all on ZFS ???
Can I create a new VM using the correct snapshot as a starting point, and if so, what is the exact syntax to do this. Somewhere along the way I seem to have also created a -bak with no snapshots? So now I have 3 instances of this VM.