From owner-freebsd-current@FreeBSD.ORG Wed Feb 25 07:15:48 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 232B41065672; Wed, 25 Feb 2009 07:15:48 +0000 (UTC) (envelope-from lstewart@freebsd.org) Received: from lauren.room52.net (lauren.room52.net [210.50.193.198]) by mx1.freebsd.org (Postfix) with ESMTP id A42C08FC18; Wed, 25 Feb 2009 07:15:47 +0000 (UTC) (envelope-from lstewart@freebsd.org) Received: from lstewart.caia.swin.edu.au (lstewart.caia.swin.edu.au [136.186.229.95]) (authenticated bits=0) by lauren.room52.net (8.14.3/8.14.3) with ESMTP id n1P7FKvl059840 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 25 Feb 2009 18:15:21 +1100 (EST) (envelope-from lstewart@freebsd.org) Message-ID: <49A4F003.7060902@freebsd.org> Date: Wed, 25 Feb 2009 18:15:15 +1100 From: Lawrence Stewart User-Agent: Thunderbird 2.0.0.19 (X11/20090213) MIME-Version: 1.0 To: Matthew Seaman References: <1235502625.4345.2.camel@localhost.localdomain> <20090224192950.GA93786@crodrigues.org> <49A458BF.8090603@freebsd.org> <49A4B8A6.80303@freebsd.org> <49A4E7B6.3010304@infracaninophile.co.uk> In-Reply-To: <49A4E7B6.3010304@infracaninophile.co.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_SOFTFAIL autolearn=disabled version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on lauren.room52.net Cc: Craig Rodrigues , Tim Kientzle , FreeBSD Current , Sean Bruno Subject: Re: Default FS Layout Too Small? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Feb 2009 07:15:48 -0000 Hi Matthew, Matthew Seaman wrote: > Lawrence Stewart wrote: > >> When I last played around with having 1 large partition in the 6.1 >> days, it didn't actually work consistently. From memory the issue is >> that if the boot filesystem (which was on the large root partition) >> extended past a particular combination of cyl/head/sector, the machine >> would crash in the boot stage. With a 20GB disk it was fine, but a >> 40GB disk would trigger the crash. >> >> This may have been fixed since then, but it would be worth doing some >> testing on a range of hardware before we could recommend it as an option. > > A counter point: we have several hundred servers of various makes[*], sizes > and ages -- most OS versions since 4.11 right up to 7.1-p3, typically with > 40+ GB HDDs for the system disk (depending on age -- the most recent > machines > have 160GB) -- all laid out in the all-in-one fashion and we've never > seen the > problem described. I can only suppose Lawrence ran into a specific > motherboard > or BIOS limitation. > Thanks for the info; it's good to hear you've had no issues with a broad base of hardware/software. I think the "crappy BIOS" option is indeed the most likely cause. In trying to remember more details (was back on 2006), I found this in boot(8) which I think might have been related to what I eventually tracked down: ########## NOTE: On older machines, or otherwise where EDD support (disk packet interface support) is not available, all boot-related files and structures (including the kernel) that need to be accessed during the boot phase must reside on the disk at or below cylinder 1023 (as the BIOS understands the geometry). When a ``Disk error 0x1'' is reported by the second-stage bootstrap, it generally means that this requirement has not been adhered to. ########## The machine I was working with was P3 vintage, and I think I saw it on an early P4 as well, so whilst modern hardware is most likely not affected, older motherboards/BIOSes might still be. I still use P3's for home gateway setups and the like. Anyway, worth having on record in this thread nonetheless, but happy to hear it's not an issue with more recent hardware. Cheers, Lawrence