Hello everyone, The unstable tree is still format compatible with v0.14, and it now includes the ability to remove devices online. In mirror configurations, IO errors to one of the mirrors are also handled, although it doesn't currently kick off a rebuild or other magic.
To try things out: mkfs.btrfs -d raid1 -m raid1 /dev/sdb /dev/sdc mount /dev/sdb /mnt # put data on /mnt # then add /dev/sdd to the FS btrfs-vol -a /dev/sdd /mnt At this point we've got a raid1 filesystem with data spread across sdb and sdc. If we remove /dev/sdc, all the existing data will be remirrored onto sdd: btrfs-vol -r /dev/sdc /mnt There is also a mount -o degraded to handle situations where a device in the FS has been lost or removed: mkfs.btrfs -d raid1 -m raid1 /dev/sd[bc] mount /dev/sdb /mnt # put data on /mnt umount /mnt # corrupt the drive dd if=/dev/zero of=/dev/sdc bs=1M count=1000 # this mount will fail, dmesg will show that not enough devices were found mount /dev/sdb /mnt # this mount will succeed, but only one device will be used mount -o degraded /dev/sdb /mnt # add a spare btrfs-vol -a /dev/sdd /mnt # remove the corrupted drive btrfs-vol -r missing /mnt btrfs-vol -r missing is a special command that tells btrfs to reconstruct things without the first device it can find that is mentioned in the metadata but not present in the mounted FS. I plan on hammering on this for a bit and then cutting v0.15 -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
