From: davidsen@ariel.crd.GE.COM (william E Davidsen) Subject: Re: Device names (was Re: ttys2 not responding) Date: 22 Jul 1992 14:37:05 GMT
In article <711742044.F00069@remote.halcyon.com>, Rob.Levin@f217.n3802.z1.fidonet.org (Rob Levin) writes:
|> Could you be more specific on the BSD convention for hard disk naming?
|> And for partitions, if such a thing exists in the vanilla BSD
|> environment?
Let me try to explain several ways in which disks are named, all of
which seem to me to be better than the way it's currently done in linux.
Many BSD systems call their drives hd#P (where # is the drive # and P
is the partition). Many have conventions that partition c is the whole
disk. SCO uses the drive number and partition number (rather than
letter), reserving the letters for a=all and d=dos (as I recall).
Some systems include the controller number on the id, like V.4, where
a device might be c0d0s3 (controller 0, device 0, slice 3).
What I think might improve the information content of names is to
include the controller and device number as digits, then the partitions
as lower case characters, reserving the character A of the whole (ALL)
disk. This would give hd00a, hd00b, etc, hd00A the whole disk, hd01a the
2nd disk, etc. hd10a would be the 2nd controller, drive 0. I think
that's important in the near term, because there are a lot of smaller
drives becoming available and people need a 2nd controller to run more
than 2 drives.
Since I'm probably going to get flamed for this anyway, I think the
SCO floppy naming conventions are useful, if somewhat verbose. They're
easy to remember because they contain tpi, spt, etc. fd096ds15 is device
0, 96 tpi (HD), double sided, 15 spt. The raw (character) device has an
'r' added to the front of the device name.
While that's not optimal for linux (no one runs linux on single sided
disks, do they?), I think the names in use now may have less than optimal
information, and could be improved. I leave it to someone else to pick
names which reflext the mimits of the existing device drivers.
--
bill davidsen, GE Corp. R&D Center; Box 8; Schenectady NY 12345
It never ceases to amaze me that otherwise rational people, able to
understand calculus, compound interest, and the income tax form, can
continue to believe that poker is a game of chance.