Home / server / Questions / 295752
Accepted
Déjà vu
Asked: 2011-07-30 21:00:33 +0800 CST

Linux boot: md raid FS not ready (sometimes)

  • 772

Using Ubuntu 11.04 (latest patched)

I have 5 RAID-1 file systems that are automatically assembled during the boot process

(Note: none of the system FS /, /usr... are raid, only user FSes).

Once in a while, during boot, an MD cannot be assembled (seemingly) and Ubuntu asks
(edit: exact message)

 The disk drive for '/home/development' is not ready yet or is not present.
 You may keep waiting; Skip the drive; Manual recovery

But the FS will never be ready. After a reboot, it usually becomes available.
It happens sometimes - not always the same MD - I saw quickly that a FS was being checked just before it happened today.

It seems to be a kind of race condition between mdadm and the FS checking system, and this would be a bug IMO.
edit It happens sometimes, even if no FS was being checked...

Any idea?

mdadm.conf:

 ARRAY /dev/md0 level=raid1 num-devices=2 metadata=00.90 UUID=121f2e3b:415a1234:abcdb5ce:5f9876d3
 ...

fstab:

 /dev/md0 /home/development ext4    defaults,relatime        1       2
 ...

Edit Feb 2012

I don't think it is a bug per se. Even in Ubuntu 11.10 (latest as of today) the problem persists (and none of my drives / FS are corrupted).

It is very likely to be related to the rc.d order of operations.
It seems the drives are still being checked, or are not ready yet for some reasons, while mdadm tries - too early - to make the associations between the two disks, and fails.

Any new idea is welcome.

linux ubuntu raid boot md

3 Answers

  1. Yes, it's a bug. Report it to Ubuntu unless you feel like fixing it yourself.

    • 2

  2. From the fstab(5) man page:

    The fourth field (fs_mntops):

    ...

    nofail
    do not report errors for this device if it does not exist.

    If you add this option, the error shouldn't appear, but the fs should be mounted when it's ready.

    • 0
  3. Best Answer

    Finally I found two answers.

    1. The answer (update 2012-05-02)

    There was a problem after the update from Ubuntu 11.04 to 11.10. And the MD arrays are not ready yet, when they are tested by the system. A race condition.

    The solution was on ubuntuforums.org

    1. Floppy disk problem

      Opened the box, and

      • checked all cables and connections. Same problem after reboot.
      • The (S.M.A.R.T enabled) disks showed no problem anyway.
      • Tested the memory: ok

    I tried to remove some external connections, and when I did for the floppy disk... The boot was faster and clean. Did it several times, cold start after removing power cable etc... OK!

    So the culprit was the floopy disk. Not sure if it is an issue with the MB (Gigabyte P55-UD3R), Ubuntu (don't think so) or the floppy drive itself - and I didn't notice any relevant log that could lead to a hardware issue.

    • 0