Why is my RAID /dev/md1 showing up as /dev/md126? Is mdadm.conf being ignored?
- by mmorris
I created a RAID with:
sudo mdadm --create --verbose /dev/md1 --level=mirror --raid-devices=2 /dev/sdb1 /dev/sdc1
sudo mdadm --create --verbose /dev/md2 --level=mirror --raid-devices=2 /dev/sdb2 /dev/sdc2
sudo mdadm --detail --scan returns:
ARRAY /dev/md1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e
ARRAY /dev/md2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb
Which I appended it to /etc/mdadm/mdadm.conf, see below:
# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#
# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan, using
# wildcards if desired.
#DEVICE partitions containers
# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes
# automatically tag new arrays as belonging to the local system
HOMEHOST <system>
# instruct the monitoring daemon where to send mail alerts
MAILADDR root
# definitions of existing MD arrays
# This file was auto-generated on Mon, 29 Oct 2012 16:06:12 -0500
# by mkconf $Id$
ARRAY /dev/md1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e
ARRAY /dev/md2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb
cat /proc/mdstat returns:
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md2 : active raid1 sdb2[0] sdc2[1]
208629632 blocks super 1.2 [2/2] [UU]
md1 : active raid1 sdb1[0] sdc1[1]
767868736 blocks super 1.2 [2/2] [UU]
unused devices: <none>
ls -la /dev | grep md returns:
brw-rw---- 1 root disk 9, 1 Oct 30 11:06 md1
brw-rw---- 1 root disk 9, 2 Oct 30 11:06 md2
So I think all is good and I reboot.
After the reboot, /dev/md1 is now /dev/md126 and /dev/md2 is now /dev/md127?????
sudo mdadm --detail --scan returns:
ARRAY /dev/md/ion:1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e
ARRAY /dev/md/ion:2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb
cat /proc/mdstat returns:
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md126 : active raid1 sdc2[1] sdb2[0]
208629632 blocks super 1.2 [2/2] [UU]
md127 : active (auto-read-only) raid1 sdb1[0] sdc1[1]
767868736 blocks super 1.2 [2/2] [UU]
unused devices: <none>
ls -la /dev | grep md returns:
drwxr-xr-x 2 root root 80 Oct 30 11:18 md
brw-rw---- 1 root disk 9, 126 Oct 30 11:18 md126
brw-rw---- 1 root disk 9, 127 Oct 30 11:18 md127
All is not lost, I:
sudo mdadm --stop /dev/md126
sudo mdadm --stop /dev/md127
sudo mdadm --assemble --verbose /dev/md1 /dev/sdb1 /dev/sdc1
sudo mdadm --assemble --verbose /dev/md2 /dev/sdb2 /dev/sdc2
and verify everything:
sudo mdadm --detail --scan returns:
ARRAY /dev/md1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e
ARRAY /dev/md2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb
cat /proc/mdstat returns:
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md2 : active raid1 sdb2[0] sdc2[1]
208629632 blocks super 1.2 [2/2] [UU]
md1 : active raid1 sdb1[0] sdc1[1]
767868736 blocks super 1.2 [2/2] [UU]
unused devices: <none>
ls -la /dev | grep md returns:
brw-rw---- 1 root disk 9, 1 Oct 30 11:26 md1
brw-rw---- 1 root disk 9, 2 Oct 30 11:26 md2
So once again, I think all is good and I reboot.
Again, after the reboot, /dev/md1 is /dev/md126 and /dev/md2 is /dev/md127?????
sudo mdadm --detail --scan returns:
ARRAY /dev/md/ion:1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e
ARRAY /dev/md/ion:2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb
cat /proc/mdstat returns:
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md126 : active raid1 sdc2[1] sdb2[0]
208629632 blocks super 1.2 [2/2] [UU]
md127 : active (auto-read-only) raid1 sdb1[0] sdc1[1]
767868736 blocks super 1.2 [2/2] [UU]
unused devices: <none>
ls -la /dev | grep md returns:
drwxr-xr-x 2 root root 80 Oct 30 11:42 md
brw-rw---- 1 root disk 9, 126 Oct 30 11:42 md126
brw-rw---- 1 root disk 9, 127 Oct 30 11:42 md127
What am I missing here?
