Snapshotting running Virtualbox instances...
...seems very difficult. I tried the script listed here:
Arne's Blog: Backup of running VirtualBox machines
but I end up with corrupt stuff, including the entire Virtual machine. VBoxManage says it cannot delete the deleteme copy and then it all goes downhill from there.
I am probably doing something wrong, but I am now looking at KVM or Xen to see if they can do snapshots. This is a lot trickier than I thought. Maybe I will need to settle for stopping the Virtualbox vm, back it up and then start it again, or somehow back up its entire state from within itself. But that does not feel right.
I'm also looking into using a snapshotting file system such as btrfs for snapshotting VM state, but btrfs has a lot of problems in this context according to this thread: