mdadm: Failed to assemble all arrays

[David Andel]

On Thu, 4 Mar 2010 09:04:53 +0100, martin f krafft <madduck at debian.org>
wrote:
> 
> In that case your most likely problem is that mdadm.conf is out of
> date. Use the output of /usr/share/mdadm/mkconf .

I have made one with the latest version (in the chroot which is read
during boot):

root at Microknoppix:/# tail -2 /etc/mdadm/mdadm.conf
# This configuration was auto-generated on Sat, 20 Feb 2010 20:50:01 +0100
# by mkconf 3.1.1-1+incremental+4

> Try rootdelay=20 instead of =1.

That did not change anything.

> If you are at the shell, can you assemble arrays with mdadm -A ?

When in Knoppix this is no problem. Both mdadm versions work fine, i.e.
the Knoppix version and version 3.1.1-1+incremental+4 in the chroot.

For comparison purposes here the output when assembling an array manually
using the version in question (3.1.1-1+incremental+4):

root at Microknoppix:/# mdadm -C /dev/md0 -l1 -n2 /dev/sd[ab]1
mdadm: /dev/sda1 appears to contain an ext2fs file system
    size=64128K  mtime=Thu Mar  4 22:55:21 2010
mdadm: /dev/sda1 appears to be part of a raid array:
    level=raid1 devices=2 ctime=Thu Mar  4 22:13:40 2010
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/' or '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=1.0
mdadm: /dev/sdb1 appears to contain an ext2fs file system
    size=64128K  mtime=Thu Mar  4 22:55:21 2010
mdadm: /dev/sdb1 appears to be part of a raid array:
    level=raid1 devices=2 ctime=Thu Mar  4 22:13:40 2010
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/' or '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=1.0
Continue creating array? y
mdadm: Defaulting to version 1.1 metadata
mdadm: array /dev/md0 started.
root at Microknoppix:/# 

This looks fine, and it works.

HOWEVER: during boot I've got the following message:
...
Begin: Mounting root file system... Begin: Running /scripts/local-top...
Begin: LoadingSuccess: loaded MD module.
Begin: Assembling all MD arrays... Failure: failed to assemble all arrays.
done.
done.
Begin: Waiting for root file system... done.
Gave up waiting for root device.
...

And falling back to the initramfs shell. When assembling an array manually
there I get:

(initramfs) mdadm -C /dev/md0 -l1 -n2 /dev/sd[ab]1
...
raid1: md0 is not clean -- starting background reconstruction
md0: unknown partition table
(initramfs) mount /dev/md0 /boot
mount: mounting /dev/md0 on /boot/ failed: No such file or directory


It also is interesting that there are no /dev/mdx devices there after that
halfway boot and also no /boot directory.
However, the system must have assembled and read the array consisting of
/dev/sd[ab]1 since the kernel is living there...

I have searched around a lot and did not find a solution.
I also do not think that the metadata version can be the problem since
it's not grub which is complaining.

How can I investigate further?

Thanks, David