Subject: Re: Why not change disk naming?
To: Iggy Drougge <optimus@canit.se>
From: Nate Johnston <natej@aol.net>
List: netbsd-users
Date: 12/28/2001 12:06:57
Iggy Drougge spake thus: (Fri, Dec 28, 2001 at 03:42:43PM +0100)

> Isn't the slice concept an i386-specific thing to work around the
> limited
> number of partitions allowed?
  
Well, I guess "slice" <= "partition" is an i386 thing.  In other
architectures "slice" == "partition".   

For example, partitions in Solaris are named cXtXdXsX, where

c = controller
t = target
d = disk
s = slice

so you can always locate the exact physical slice being referenced.
This kind of granularity is important if, for example, you have 2 SCSI
cards (c0 and c1), with an external raid array for each (c0t0 and c1t0),
each has 12 disks, with three slices each, and you want to directly
address them.  How would we do the equivalent of /dev/disk/c1t0d9s3 in
solaris?

"Nobody would ever have this configuration without using RAID to stripe
the disks together." and it's variants are not valid answers.  I've had
to, more than once.

--N.