rsync -avhHPx --delete source/dir destdir/
Me: Oh no! The correct source was source/ - not source/dir - and now all of destdir's contents (4.6 TB) have been deleted!
Me, two seconds later: Oh well. `zfs rollback datapool/dataset@lastSnap`
rsync -avhHPx --delete source/ destdir/
Thank you, ZFS.