From owner-freebsd-stable@FreeBSD.ORG Sun Aug 1 15:36:19 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4A68416A4CE; Sun, 1 Aug 2004 15:36:19 +0000 (GMT) Received: from grant.org (grant.org [206.190.173.18]) by mx1.FreeBSD.org (Postfix) with ESMTP id 01A1D43D1F; Sun, 1 Aug 2004 15:36:19 +0000 (GMT) (envelope-from mgrant@grant.org) Received: from grant.org (localhost [127.0.0.1]) by grant.org (8.12.11/8.12.11) with ESMTP id i71FaEDm037832 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 1 Aug 2004 11:36:14 -0400 (EDT) (envelope-from mgrant@grant.org) Received: (from mgrant@localhost) by grant.org (8.12.11/8.12.11/Submit) id i71FaA2W037811; Sun, 1 Aug 2004 11:36:10 -0400 (EDT) (envelope-from mgrant) Date: Sun, 1 Aug 2004 11:36:10 -0400 From: Michael Grant To: Scott Long Message-ID: <20040801153610.GE80016@grant.org> References: <20040801084545.T32601@pooker.samsco.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040801084545.T32601@pooker.samsco.org> User-Agent: Mutt/1.4.1i X-Virus-Scanned: by amavisd-new cc: freebsd-stable@freebsd.org cc: Pete French Subject: Re: How does CAM determine the order to number drives ? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Aug 2004 15:36:19 -0000 Now I'm a little confused. If you have 2 of the same scsi controller (say 2 adaptec 2940s), how can you possibly distinguish them apart? One problem I had once was one of the 2940s died and my second 2940 became my first. I don't really see how one can fix this sort of thing in the kernel unless you can specifically identify which controller is which. I just want to toss this out as an idea: Would it be possible to put some identifier somewhere on the drive itself when you partition the drive such that the drive itself could always come up in the same place regardless even if it moved to a different controller? Michael Grant On Sun, Aug 01, 2004 at 08:49:58AM -0600, Scott Long wrote: > On Sun, 1 Aug 2004, Pete French wrote: > > > You can wire down particular devices to a given SCSI bus, target and > > > LUN. Thus in your (4.x) kernel config you can say: > > > > > > device scbus0 at ahc0 > > > device da0 at scbus0 target 0 unit 0 > > > > Thanks for this - it looked as though it was just what I needed. I built > > a kernel with scbus0 placed at ahc? (ahc0 would not compile - but I only > > have one Adaptec controller in the machine). I would have thought this > > was sufficient as it would then scan scbus0 first and thus find the > > Addapted conntected drive first. But it did not appear to do this - I > > still had the ciss drives appearing first. > > You need to explicitely define 'ahc0' as so: > > device ahc > device ahc0 /* declared for wiring */ > device scbus > device scbus0 at ahc0 > > Wiring down the controller number doesn't usually affect drive ordering. > All drives on all controllers are scanned at once in parallel, and the > first to respond on any controller, regardless of the controller number, > get to be da0. > > Scott