On Thursday 10 April 2014 13:58:45 Duncan wrote: > Michael Schuerig posted on Thu, 10 Apr 2014 15:21:01 +0200 as excerpted: > > SMART indicates that my notebook disk may soon be failing (an > > unreadable/uncorrectable sector), therefore I intend to exchange it. > > The disk contains a single btrfs filesystem with several nested(!) > > subvolumes, each with several read-only snapshots in a .snapshots > > subdirectory. > > > > As far as I can tell, btrfs currently does not offer a sensible way > > to duplicate the entire contents of the old disk onto a new one. I > > can use cp, rsync, or send/receive to copy the "main" subvolumes. > > But unless I'm missing something obvious, the snapshots are > > effectively lost. btrfs send optionally takes multiple clone > > sources, but I've never seen an example of its usage. > > > > If that's what "experimental" means, I'm willing to accept it. > > However, I'd like to emphasize that there's still something > > missing. Of course, most of all I'd like to be proved wrong. > > It's not a btrfs tool, but several of the tools you mentioned aren't, > and you didn't mention dd (or ddrescue, if your source device starts > giving you issues while you're cloning). Using it you'd clone the > entire raw device, including any not yet allocated areas, in a > straight-across bit- perfect copy. Of course you'd need a target of > either the same size or larger in ordered to do so... > > That should give you a bit-perfect copy including the filesystem > UUIDs, etc, which will confuse btrfs if you try to mount anything > btrfs with both devices attached, so don't. Do your clone, then > umount and disconnect the old device before trying to mount the new > one. Thanks for pointing out dd and especially ddrescue, which I didn't know. I regularly use dd to copy images onto USB thumb drives, but I'm a bit wary regarding its use on hard disks. I've always been concerned that if I get another disk, not necessarily of the same make, that has nominally the same capacity, it still might be a few blocks smaller. Well, I just found one that has the right size, apparently. Thanks again, Michael -- Michael Schuerig mailto:michael@xxxxxxxxxxx http://www.schuerig.de/michael/ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
