From owner-freebsd-questions@FreeBSD.ORG  Tue Feb 15 14:45:15 2005
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 5BE4516A4CE
	for <freebsd-questions@freebsd.org>;
	Tue, 15 Feb 2005 14:45:15 +0000 (GMT)
Received: from mail28.sea5.speakeasy.net (mail28.sea5.speakeasy.net
	[69.17.117.30])	by mx1.FreeBSD.org (Postfix) with ESMTP id 0DFE043D1F
	for <freebsd-questions@freebsd.org>;
	Tue, 15 Feb 2005 14:45:15 +0000 (GMT)
	(envelope-from freebsd-questions-local@be-well.ilk.org)
Received: (qmail 16455 invoked from network); 15 Feb 2005 14:45:14 -0000
Received: from dsl092-078-145.bos1.dsl.speakeasy.net (HELO be-well.ilk.org)
	([66.92.78.145])
	(envelope-sender <freebsd-questions-local@be-well.ilk.org>)
	by mail28.sea5.speakeasy.net (qmail-ldap-1.03) with SMTP
	for <freebsd-questions@freebsd.org>; 15 Feb 2005 14:45:14 -0000
Received: by be-well.ilk.org (Postfix, from userid 1147)
	id BC08B7E; Tue, 15 Feb 2005 09:45:13 -0500 (EST)
Sender: lowell@be-well.ilk.org
To: Mike Jeays <Mike.Jeays@rogers.com>
References: <1108353173.33317.10.camel@chaucer.jeays.ca>
From: Lowell Gilbert <freebsd-questions-local@be-well.ilk.org>
Date: 15 Feb 2005 09:45:13 -0500
In-Reply-To: <1108353173.33317.10.camel@chaucer.jeays.ca>
Message-ID: <44fyzx287a.fsf@be-well.ilk.org>
Lines: 31
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
cc: freebsd-questions@freebsd.org
Subject: Re: SCSI device numbers
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 15 Feb 2005 14:45:15 -0000

Mike Jeays <Mike.Jeays@rogers.com> writes:

> I have at present two emulated SCSI devices on my system; a USB flash
> drive, and a DVD-writer.
> 
> They get assigned:
>  
>  0,0,0     0) 'SanDisk ' 'Cruzer Micro    ' '2033' Removable Disk
>  2,0,0   200) 'HL-DT-ST' 'DVDRAM GSA-4160B' 'A300' Removable CD-ROM
> 
> if the USB device is present at boot time (I think).
> 
> So my script for burning CDs, which says:
>   mkisofs -J -L -R -o x1.iso "$*"
>   cdrecord -v dev=2,0,0 x1.iso
>   rm -f x1.iso
> is very fragile.
> 
> How should I do it?  Write a script to read the output of cdrecord
> -scanbus and grab the device number?  There has to be a "right" way, and
> instinct says this isn't it.

It's not a bad way.  

I'm not sure I understand why the device numbering is so fragile,
though; wouldn't the ATAPI buses available at boot time be the same
whether they have devices or not?

-- 
Lowell Gilbert, embedded/networking software engineer, Boston area
		http://be-well.ilk.org/~lowell/