In the zfs man page with nv 76, it warns us about use of -r and -f options as they can make very big changes. The warning does NOT mention -R. -R destroys "dependents" rather than "children" (but then adds in some other things); is that why the warning applies to -r but not to -R? The description of what actually happens in the snapshot case appears to be the same, though. Text I get from man is this: zfs destroy [-rRf] filesystem|volume|snapshot Destroys the given dataset. By default, the command unshares any file systems that are currently shared, unmounts any file systems that are currently mounted, and refuses to destroy a dataset that has active depen- dents (children, snapshots, clones). -r Recursively destroy all children. If a snapshot is specified, destroy all snapshots with this name in descendent file systems. -R Recursively destroy all dependents, including cloned file systems outside the target hierarchy. If a snapshot is specified, destroy all snapshots with this name in descendent file systems. -f Force an unmount of any file systems using the "unmount -f" command. This option has no effect on non-file systems or unmounted file systems. Extreme care should be taken when applying either the -r or the -f options, as they can destroy large portions of a pool and cause unexpected behavior for mounted file systems in use. -- David Dyer-Bennet, dd-b at dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info