On Wed, Jul 17, 2013 at 11:24:22PM +0200, Florian Lindner wrote: > I create a btrfs volume comprised of two partitions: > > # mkfs.btrfs -m dup -d single /dev/sdd1 /dev/sde1 DUP does not work on multiple devices, I assume you mean RAID1. > metadata ist mirrored on each device, data chunks are scattered more or less > randomly on one disk. > > a) If one disk fails, is there any chance of data recovery? > b) If not, is there any advantage over a raid0 configuration. Regarding data layout, raid0 will always place the small (64k) chunks on multiple devices, with single this does not happen every time and the data are spread in larger contiguous chunks on each of the device. Rewriting data makes the placement unpredictable, so it may end up random. The missing data blocks return IO error and the valid data can be read. david -- 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
