On Thursday October 5, madduck@xxxxxxxxxxx wrote:
>
> Unfortunately, mdadm (2.5.3) doesn't seem to agree; it complains
> that it cannot assemble a RAID10 with 4 devices when I ask it to:
>
> mdadm --create -l 10 -n4 -pn2 /dev/md1 /dev/sd[cd] missing missing
>
mdadm --create -l 10 -n 4 -pn2 /dev/md1 /dev/sdc missing /dev/sdd missing
Raid10 lays out data like
A A B B
C C D D
not
A B A B
C D C D
as you seem to expect.
So you could even do
mdadm --create -l 10 -n 4 -pn2 /dev/md1 missing /dev/sd[cd] missing
for slightly less typing.
There seems to be a bug in raid10 that is reports the wrong number of
working drives. This is probably only in 2.6.18. Patch is below.
NeilBrown
Signed-off-by: Neil Brown <neilb@xxxxxxx>
### Diffstat output
./drivers/md/raid10.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff .prev/drivers/md/raid10.c ./drivers/md/raid10.c
--- .prev/drivers/md/raid10.c 2006-09-29 11:44:36.000000000 +1000
+++ ./drivers/md/raid10.c 2006-10-05 20:10:07.000000000 +1000
@@ -2079,7 +2079,7 @@ static int run(mddev_t *mddev)
disk = conf->mirrors + i;
if (!disk->rdev ||
- !test_bit(In_sync, &rdev->flags)) {
+ !test_bit(In_sync, &disk->rdev->flags)) {
disk->head_position = 0;
mddev->degraded++;
}
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
