I'm trying to create a RAID1 array on my WL-500gP, but I'm only partly successfull.

I'm running lastest oleg firmware (1.9.2.7-7f), and I'm using the oleg optware repository.

My crosscompile environment is VMware running Fedora core 6 (with gcc 3.4 instead of 4.1)



Steps I've taken :

- Recompile the firmware, with Multi-device support and RAID1 support enabled as modules.
(I also had to disable LPRng, otherwise the firmware wouldn't build)

- copy md.o and raid1.o from the crosscompile pc to /opt/lib/modules on the router

- Compile mdadm:
While crosscompiling, 'make mdadm' & 'make mdadm-ipk' both build fine, but installing mdadm_2.6-1_mipsel.ipk on the router fails on a md5-checksum
While native compiling, 'make mdadm' builds fine, but 'make mdadm-ipk' fails.
So I manually copied mdadm from optware/builds/mdadm/ to /opt/sbin

- Load the raid modules:
insmod /opt/lib/modules/md.o
insmod /opt/lib/modules/raid1.o

- for test purposes, I attached a usb-cardreader, with a 128 MB sd-card and a 128 MB cf-card.
- on both discs I created one partition of 122 MB , type fb (Linux raid autodetect)

-next step would be the creation of the raid-array:

mknod /dev/md0 b 9 0
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/discs/disc1/part1 /dev/discs/disc3/part1

However this fails with the error:
mdadm: ADD_NEW_DISK for /dev/discs/disc1/part1 failed: Invalid argument

In the systemlog, I get the following messages:
kernel: md: invalid superblock checksum on scsi/host1/bus0/target0/lun0/part1
kernel: md: scsi/host1/bus0/target0/lun0/part1 has invalid sb, not importing!
kernel: md: md_import_device returned -22

The only raid-array I can create is a legacy array without a superblock:

mknod /dev/md0 b 9 0
mdadm --build /dev/md0 --level=1 --raid-devices=2 /dev/discs/disc1/part1 /dev/discs/disc3/part1

after that, I can see the array being build, using cat /proc/mdstat


Questions:
- what could be the reason that i can't build an array with superblocks?
(could it be that mdadm isn't compatible with the raid modules?)

- what are the risks when running a mirror without superblocks?