With btrfs, we can't really put the log on a separate device. What we can do however is mirror the metadata across two devices and put the data on a single device. When we turn on dmerror then the metadata can fall back to using the other mirror while the data errors out. Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- common/rc | 2 ++ 1 file changed, 2 insertions(+) diff --git a/common/rc b/common/rc index 8b815d9c8c33..2084c1f24f30 100644 --- a/common/rc +++ b/common/rc @@ -829,6 +829,8 @@ _scratch_mkfs() ;; btrfs) mkfs_cmd="$MKFS_BTRFS_PROG" + [ "$USE_EXTERNAL" = yes -a ! -z "$SCRATCH_LOGDEV" ] && \ + mkfs_cmd="$mkfs_cmd -d single -m raid1 $SCRATCH_LOGDEV" mkfs_filter="cat" ;; ext2|ext3) -- 2.9.3
