mdadm failed to autocreate md /dev entries
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| mdadm (Ubuntu) |
New
|
Undecided
|
Unassigned | ||
Bug Description
I've just upgraded from 10.11 to 11.04
I have the following mdadm.conf(worked like a charm for 10.11):
DEVICE partitions
CREATE owner=root group=disk mode=0660 auto=yes
HOMEHOST <system>
MAILADDR root
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=78bab575:
After upgrade i have the following mdstat:
$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : inactive md127p1[0](S)
488383936 blocks
md127 : active (auto-read-only) raid1 sdc[1] sdb[0]
488386496 blocks [2/2] [UU]
unused devices: <none>
Two get my raid1 up and running i have to do the following:
$sudo mdadm --stop /dev/md0
$sudo mdadm --stop /dev/md127
$sudo mdadm --assemble /dev/md0 /dev/sdb1 /dev/sdc1
$sudo mount /dev/md0 /mnt/raid
cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb1[0] sdc1[1]
488383936 blocks [2/2] [UU]
unused devices: <none>
$ sudo mdadm --detail --scan --verbose
ARRAY /dev/md0 level=raid1 num-devices=2 metadata=0.90 UUID=78bab575:
devices=
How can I get mdadm autodetection work as expected?
Best regards,
Dmitry
| m0sia (m0sia) wrote | #1 |
It seems i found the root cause of the initial problem: there were a pair of raid superblocks on each hard drive(ex in both /dev/sdb and /dev/sdb1). Until 11.04 it somehow worked for me.
Now i've removed the unnecessary raid superblocks and everything works.
sudo mdadm --zero-superblock /dev/sdb
sudo mdadm --zero-superblock /dev/sdc
But i still wonder if it is a bug or a feature.