Hi, the current discussion on how to implement "undo" seems to circulate around concepts and tweaks for replacing any "rm" like action with "mv" and then fix the problems associated with namespaces, ACLs etc.
Why not use snapshots? A snapshot-oriented implementation of undo would: - Create a snapshot of the FS whenever anything is attempted that someone might want to undo. This could be done even at the most fundamental level (i.e. before any "zpool" or "zfs" command, where the potential damage to be undone is biggest). - The undo-feature would then exchange the live FS with the snapshot taken prior to the revoked action. Just tweak one or two pointers and the undo is done. - This would transparently work with any app, user action, even admin action, depending on where the snapshotting code would be hooked up to. - As an alternative to undo, the user can browse the .zfs hierarchy in search of that small file which got lost in an rm -rf orgy without having to restore the snapshot with all the other unwanted files. - When ZFS wants to reclaim blocks, it would start deleting the oldest undo-snapshots. - To separate undo-snapshots from user-triggered ones, the undo-code could place its snapshots in .zfs/snapshots/undo . Did I miss something why undo can't be implemented with snapshots? Best regards, Constantin -- Constantin Gonzalez Sun Microsystems GmbH, Germany Platform Technology Group, Client Solutions http://www.sun.de/ Tel.: +49 89/4 60 08-25 91 http://blogs.sun.com/constantin/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
