[KLUG Members] Harddrive Imaging

[Adam Williams]

>A neat trick you can do with HP-UX is to "freeze" the filesystem at a
>consistent state before (and during) a backup.  The system keeps
>running, but all filesystem changes go into a journal.  When the backup
>is done, you unfreeze the filesystem and the journal is rolled forward
>and the filesystem is really updated.  That's one thing I haven't seen
>for Linux yet (but I haven't really looked very hard for it).  Hopefully
>it'll be a feature someday.  Anyone every hear of this being on any
>filesystem's "todo" list?  (or "done" list? :)

It isn't on the to do list, it is done.

LVM supports snapshotting, not the same as you describe, but same
purpose.

XFS supports freezing, exactly like what you describe above.  man
xfs_freeze