It seems I also have the device nodes: # ls -l /dev/md0* brw-r----- 2 root 0 17, 0 Apr 18 12:15 /dev/md0a brw-r----- 1 root 0 17, 3 Apr 18 12:15 /dev/md0d where did you get these from? looks like i386? on evbmips block major 17 is ld(4) not md(4). you want char major 28 and block major 6. see sys/arch/evbmips/conf/majors.evbmips. .mrg.