Filesystem checkpointing/snapshotting is one of the nice things about ZFS. If the OS supports ZFS on boot drives, you can do checkpointed full system/kernel up

Filesystem checkpointing/snapshotting is one of the nice things about ZFS. If the OS supports ZFS on boot drives, you can do checkpointed full system/kernel upgrades. I like your idea about process checkpointing. Of course any side effects (eventually we're only talking about network in/out) would be nonreversible, but would be theoretically replayable (have to checkpoint the RTC too). The other side of the connection might have other ideas... Sounds like a dream debugging tool though.