On Sun, 24 Apr 2011 12:57:56 +0100 John Robinson
[off-list ref] wrote:

On 24/04/2011 09:41, NeilBrown wrote:

quoted

On Sun, 24 Apr 2011 01:06:52 -0600 John Valarti[off-list ref]  wrote:

[...]

quoted

quoted

Here you go. I warn you it is a bit long!

Thanks.  Length is no problem.

Only it doesn't make sense at all.  I cannot see how mdadm would possibly be
generating just those messages.
It appear to be rejecting each device for some reason, but it not reporting
why it is rejecting the device...

What version of mdadm is this?
    mdadm --version

I should have asked that before.

I think John said 2.6.9

Ahh, I see it.  This is a bug in there:  ->used isn't set to zero after 'dv'
is allocated.  This was fixed in 3.0.  I don't remember that bug...

I cannot see any easy way to work around that bug.
You could possibly:

  echo DEV /dev/sd[abc]2 > /tmp/mdadm.conf
  mdadm -Eb /dev/sda2 >> /tmp/mdadm.conf
  mdadm -Afvv /dev/md1 -c /tmp/mdadm.conf

I think that would work - but no promises.

 on the CentOS 5.5 rescue media. I think it's 

time to try something more recent: John, could you try SystemRescueCD 
from http://www.sysresccd.org/ and run
   mdadm -Evvs
and if that shows your RAID5 members again,
   mdadm -Afvv /dev/md1

Getting a newer mdadm is definitely a good idea.

Safest to explicitly list the devices that you want
     mdadm -Afvv /dev/md1 /dev/sd[abc]2


NeilBrown

Cheers,

John.