On Thu, Jul 01, 2010 at 11:33:59AM +0000, Lubos Kolouch wrote: > Daniel J Blueman, Thu, 01 Jul 2010 12:26:10 +0100: > >> What is the correct way to do this? > > > > The only way to do this preserving duplication is to use hardlinks > > between duplicated files (which reference counts the inode), and use > > 'rsync -H'. > > > > Dan > > But when the files are on different snaphots, does rsync see them as > hardlinked? > > A scenario - I have raid5 of say, 1TB HDDs. It contains many snapshots. > Then, few years later, new machine is bought and there are, say, 5TB > discs. > > So I need to transfer the btrfs volume to the new machine. > > But how to do it so that it looks the *same*, ie. the same snapshots? > I could of course write a custom script to create the subvolume, rsync > the files, create snapshot, rsync files, etc, > > but it would be nice if the btrfs toolset supports this by default...
This is definitely something I'm looking to add. The btrfs-progs git tree has some code that allows userland to walk the btrees and detect the duplicate files. But this is just a building block needed for the full backup program. Instead of hard links, it is possible to use reflinks with cp, which uses the cloning ioctl. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
