Software RAID for "PPC PReP Boot" partition?

Hello all,

I’m trying to convert existing Opensuse 11.1 system from ordinary “one hard-drive” installation to software-based RAID. I followed this link Migrating SLES to Software RAID1 | Novell User Communities, as well as some of the others, but…

Due to the fact that we run OpenSUSE on IBM JS20 Blade servers (Power PC-based) I’m stuck trying to mirror “PPC PReP Boot” partition /dev/sda1 as /dev/md0. It gives me the following error:

#: dd if=/dev/sdb1 of=/dev/md0
dd: writing to `/dev/md0’: No space left on device
641+0 records in
640+0 records out
327680 bytes (328 kB) copied, 0.264065 s, 1.2 MB/s

#: dd if=/dev/sdb1 of=/dev/sda1
852+0 records in
852+0 records out
436224 bytes (436 kB) copied, 0.070977 s, 6.1 MB/s

works fine

I tried to research this problem but could not find anything useful. Any recommendation will be greatly appreciated.