imsm raid is always readonly on boot

[Stefan Priebe - Profihost AG <s.priebe@profihost.ag>]

Hi,

i'm running 3.0.18 as kernel (renamed to 2.6.40) and mdadm 3.2.2.

I'm trying to get an intel fake raid running but it is always set to
readonly on boot after running
mdadm --assemble --scan --run --force --auto=yes

But i've absolutely no idea why.

My mdadm.conf:
# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan,
using
# wildcards if desired.
#DEVICE partitions containers

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes

# automatically tag new arrays as belonging to the local system
HOMEHOST <ignore>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays
ARRAY metadata=imsm UUID=24cdb70d:101f4c4b:23dfa5cb:3f176b6a
ARRAY /dev/md126 container=24cdb70d:101f4c4b:23dfa5cb:3f176b6a member=0
UUID=84aa9982:ed593d80:ee7c7f53:e2944038


~# cat /sys/block/md126/md/array_state
readonly

What's wrong? Thanks!

Stefan