[Bug 120375] Re: cannot boot raid1 with only one disk

[Francis Mak]

My server was in 8.04 LTS, having a raid 1 setup with 2 mirrored harddisk.
I have tested, if I unplug one of the disk, the raid 1 was working fine.

Sadly, after upgraded my system to 10.04.1 LTS, if I unplug one of the
disk and boot, the raid 1 become inactive.

#mdadm --detail /dev/md0
mdadm: md device /dev/md0 does not appear to be active.

# cat /proc/mdstat
md0 : inactive sdb1[0](S)

I have removed some of the messages to save space here.  In the above
case, I have unplug the sdc, the raid 1 is not working anymore.  It
treated the sdb as spare disk.

If I plug back the sdc, the raid 1 will be back to normal.  It doesn't
make any sense.

Honestly, I am not a real expert in system admin.  I implemented the
software raid is simply to protect my data in case of a harddisk
failure.  Now I need to pray for both disk working in order for this
raid 1 keeping a live.....  really frustrating.

MAY I KNOW, what I need to do to fix this problem?

Thank you very much!

-- 
You received this bug notification because you are a member of Ubuntu
Server Team, which is a subscriber of a duplicate bug (125471).
https://bugs.launchpad.net/bugs/120375

Title:
  cannot boot raid1 with only one disk