scant description for devfs - unable to create /dev/ad3* or use disklabel

[ecsd]

The transition to using devfs versus MAKEDEV is not very well documented,
and I find no way to create /dev/ad3-anything although I have a /dev/ad3
and have used "disklabel -w -r ad3 auto" to initialize it.

I wish there were an example section for devfs(8) that showed how to use
devfs to do what MAKEDEV used to do. I have seen the remark "devfs
will create the node for you", but "disklabel -e /dev/ad3d" and 
"disklabel -e /dev/ad3s1d"
fail "no such device" whereas "disklabel -e /dev/ad3" reports "operation 
not supported
by device". Perhaps I could use mknod, but I don't know what minor 
numbers to
use and doing "file ad*" doesn't show a clear pattern of assignment.

I wish MAKEDEV were not removed, as it is an easy, well-known interface
to creating device nodes - as opposed to the opaque devfs, inasmuch as, 
if I had
MAKEDEV I would be done by now whereas there is nothing in the FAQs,
nothing in the search, and nothing in the release notes that describes 
the devfs
replacement for this common operation. Now I am left guessing whether I'll
have to reboot the system to see the partitions on /dev/ad3. MAKEDEV would
just work with no fuss.

-ecsd