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From: Ollivier Robert <roberto@keltia.freenix.fr>
Message-Id: <199509270759.IAA27063@keltia.freenix.fr>
Subject: Re: Diskslice naming convention?
To: nate@rocky.sri.MT.net (Nate Williams)
Date: Wed, 27 Sep 1995 08:59:05 +0100 (MET)
Cc: hackers@FreeBSD.org, bde@FreeBSD.org
In-Reply-To: <199509262344.RAA15898@rocky.sri.MT.net> from "Nate Williams" at Sep 26, 95 05:44:17 pm
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It seems that Nate Williams said:
> So, am I right in saying that other than the 'compatability' slice of
> /dev/xd#a for the root partition, the naming scheme is as follows:

It is not only the root partition. If you have only  one FreeBSD slice on a
disk, it will use the compatibility slice.
 
> X = generic device name.
> # = disk number
> Y = slice number (ie; one of the 4 'fdisk' partions')
> 
> Xd#asY  (where 'a' could be any lower-case letter 'a-h')

Xd#sYa instead.

the 'a' is at the end and shows the partition # in the slice Y. 

> BTW - Are slices named 1-4 or 0-3?

1-4, 0 is the compatibility slice.
 
> Anyway, we create a FreeBSD slice by setting it's ID to 0xA5.  Then, we
> build a disklabel onto this 'slice' which gives us individual partitions
> on that slice.  Are there any 'special' partitions in this disklabel?

'c' is special  and indicates the whole  slice (as 'c'  indicated the whole
BSD partition in the old scheme).

> How would I read the *entire* FreeBSD portion of the slice?  How about
> the entire disk?  How do I create a FreeBSD partition which accesses a
> DOS slice?

- The FreeBSD portion of a slice is Xd#sY (I think). 
- The entire disk is Xd#. 
- FreeBSD partition to access a DOS slice is not possible. A DOS partition
  will get its own slice (e.g. the sd0s4 slice could be a DOS "partition" --
  in DOS terms). 

I hope I'm right Bruce :-)
-- 
Ollivier ROBERT    -=- The daemon is FREE! -=-    roberto@keltia.frmug.fr.net
   FreeBSD keltia.freenix.fr 2.2-CURRENT #2: Mon Sep 25 02:02:31 MET 1995