I love snapshots. The ability to do something like this warms my heart:

1. Shut down all VMs
2. Turn off VMWare
3. zfs snapshot tank/Media/VM@`hostname`-`date +%s`
4. Turn VMWare back on
5. Boot the VMs
6. Schedule the movement of the snapshot to the backup host while you are doing development work on the images you just saved

The only thing that could make this better is if I had a separate ZFS dataset for each VMFS (so I could snapshot them individually), and if I could trigger the snapshots from VMWare. Yes, VMWare Fusion has internal snapshots, but I’ve not found them all that reliable. And I’m thinking of moving to VirtualBox anyway – my ZFS snapshots live until I migrate off OpenSolaris. (Which I hope never happens).