2011-07-11 14:39:18 +0200, krzf83@xxxxxxxxx : > 2011/7/11 Stephane Chazelas <stephane_chazelas@xxxxxxxx>: [...] > > See also > > http://thread.gmane.org/gmane.comp.file-systems.btrfs/9675/focus=9820 > > for a way to transfer btrfs fs. > > > > (Add a layer of "copy-on-write" on the original devices (LVM > > snapshots, nbd/qemu-nbd cow...), "btrfs add" the new device(s) > > and then "btrfs del" of the cow'ed original devices. [...] > Copying on block level (dd, lvm) is old trick, however this takes same > ammount of time regardless of actual space used in filesystem. Hence > this feature request. Images inside filesystem can copy only actualy > used data and metadata, which dramaticly reduces copy times in large > volumes that are not filled up... The method I suggest doesn't copy the whole disks, please read more carefully. It can also work to copy from a 3 disk setup to a 1 disk setup or the other way round. With btrfs, you can add devices to a FS dynamically, you can also delete devices in which case data is being transfered to the other devices. The method I suggest uses that feature. Cheers, Stephane -- 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
