problems with raid=noautodetect

[Florian Dazinger <florian.dazinger@umit.at>]

hi list,
I read somewhere that it would be better not to rely on the 
autodetect-mechanism in the kernel at boot time, but rather to set up 
/etc/mdadm.conf accordingly and boot with raid=noautodetect. Well, I 
tried that :)

I set up /etc/mdadm.conf for my 2 raid5 arrays:

---- snip ----
# mountpoint: /home/media
ARRAY  /dev/md0
    level=raid5
    UUID=86ed1434:43380717:4abf124e:970d843a
    devices=/dev/sda1,/dev/sdb1,/dev/sdd3

# mountpoint: /mnt/raid
ARRAY  /dev/md1
    level=raid5
    UUID=baf59fb5:f4805e7a:91a77644:af3dde17
#   devices=/dev/sda2,/dev/sdb2,/dev/sdd2
---- snap ----

and rebooted with raid=noautodetect. It booted fine, but the 3rd disks 
from each array (/dev/sdd2 and /dev/sdd3) were removed, so I had 2 
degraded raid5 arrays. It was possible to readd them with sth. like:

mdadm /dev/md0 -a /dev/sdd3
(synced and /proc/mdstat showed [UUU])

but after the next reboot, the two partitions were again removed 
([UU_])?! This was a reproducible error, I tried it several times with 
different /etc/mdadm.conf settings (ARRAY-statement with UUID=, 
devices=, UUID+devices, etc.).

I´m now running autodetect again, all raid arrays are working fine, but 
can anyone explain this strange behaviour?
(kernel-2.6.16.14, amd64)

thanks,
florian

PS: please cc me, as I´m not subscribed to the list
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