From owner-freebsd-questions@FreeBSD.ORG Mon May 11 14:38:03 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 220A610656BD for ; Mon, 11 May 2009 14:38:03 +0000 (UTC) (envelope-from erikt@midgard.homeip.net) Received: from ch-smtp02.sth.basefarm.net (ch-smtp02.sth.basefarm.net [80.76.149.213]) by mx1.freebsd.org (Postfix) with ESMTP id CF0F98FC13 for ; Mon, 11 May 2009 14:38:02 +0000 (UTC) (envelope-from erikt@midgard.homeip.net) Received: from c83-255-48-78.bredband.comhem.se ([83.255.48.78]:54942 helo=falcon.midgard.homeip.net) by ch-smtp02.sth.basefarm.net with esmtp (Exim 4.69) (envelope-from ) id 1M3Wd9-0000Ez-6Y for freebsd-questions@freebsd.org; Mon, 11 May 2009 16:37:25 +0200 Received: (qmail 6838 invoked from network); 11 May 2009 16:37:19 +0200 Received: from owl.midgard.homeip.net (10.1.5.7) by falcon.midgard.homeip.net with ESMTP; 11 May 2009 16:37:19 +0200 Received: (qmail 15052 invoked by uid 1001); 11 May 2009 16:37:19 +0200 Date: Mon, 11 May 2009 16:37:19 +0200 From: Erik Trulsson To: Jonathan McKeown Message-ID: <20090511143719.GA15035@owl.midgard.homeip.net> References: <200905111630.23123.j.mckeown@ru.ac.za> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200905111630.23123.j.mckeown@ru.ac.za> User-Agent: Mutt/1.5.19 (2009-01-05) X-Originating-IP: 83.255.48.78 X-Scan-Result: No virus found in message 1M3Wd9-0000Ez-6Y. X-Scan-Signature: ch-smtp02.sth.basefarm.net 1M3Wd9-0000Ez-6Y 645a774d069ba56f076f51174cdc4413 Cc: freebsd-questions@freebsd.org Subject: Re: single SATA disk and yet identified as 'ad4' X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 May 2009 14:38:03 -0000 On Mon, May 11, 2009 at 04:30:23PM +0200, Jonathan McKeown wrote: > On Monday 11 May 2009 21:38:50 Saifi Khan wrote: > > Hi all: > > > > The system has just one SATA disk and yet bootloader process > > identified it as 'ad4'. Ideally, it should be ad1. > [snip] > > How does the labelling logic work ? > > FreeBSD reserves numbers for devices that aren't currently connected, so that > if you connect them later your existing devices don't need to be renumbered. It does this if you have 'options ATA_STATIC_ID' in your kernel config (which is the default.) Otherwise all PATA/SATA disks installed will numbered from ad0 upwards without any gaps. The drawback of that is that without the static numbering the disk devices can (and often will) be renumbered if you add or remove a disk, which often is not desirable. > > Your BIOS is reporting two IDE interfaces, each of which could have a master > and slave disk drive, so ad0-3 are reserved for those four drives, meaning > SATA starts at ad4. > > Some BIOSes let you change this. > > Jonathan -- Erik Trulsson ertr1013@student.uu.se