root # mknod /dev/md1 b 9 1
root # mknod /dev/md2 b 9 3
root # mknod /dev/md3 b 9 4

root # ls -al /dev/md*
lrwxrwxrwx 1 root root    4 Dec  2 01:31 /dev/md1 -> md/1
brw-r--r-- 1 root root 9, 3 Dec  2 01:30 /dev/md2
brw-r--r-- 1 root root 9, 4 Dec  2 01:30 /dev/md3

/dev/md:
total 0
drwxr-xr-x  2 root root   60 Dec  2 01:31 .
drwxr-xr-x 15 root root 3340 Dec  2 01:31 ..
brw-rw----  1 root disk 9, 1 Dec  2 01:31 1