From owner-freebsd-questions@FreeBSD.ORG Thu Mar 29 22:07:22 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D3B7316A407 for ; Thu, 29 Mar 2007 22:07:22 +0000 (UTC) (envelope-from fbsd-questions@mawer.org) Received: from customer-domains.icp-qv1-irony11.iinet.net.au (customer-domains.icp-qv1-irony11.iinet.net.au [203.59.1.151]) by mx1.freebsd.org (Postfix) with ESMTP id 5238713C4C1 for ; Thu, 29 Mar 2007 22:07:21 +0000 (UTC) (envelope-from fbsd-questions@mawer.org) Received: from 203-206-173-235.perm.iinet.net.au (HELO [10.24.1.1]) ([203.206.173.235]) by iinet-mail.icp-qv1-irony11.iinet.net.au with ESMTP; 30 Mar 2007 06:07:20 +0800 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAGLVC0bLzq3r/2dsb2JhbAAN X-IronPort-AV: i="4.14,348,1170601200"; d="scan'208"; a="37262544:sNHT157409184" Message-ID: <460C389B.7060703@mawer.org> Date: Fri, 30 Mar 2007 08:07:23 +1000 From: Antony Mawer User-Agent: Thunderbird 1.5.0.10 (Windows/20070221) MIME-Version: 1.0 To: Kris Kennaway References: <20070328204126.GA27217@xor.obsecurity.org> In-Reply-To: <20070328204126.GA27217@xor.obsecurity.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org, "Marc G. Fournier" Subject: Re: Why is 'disklabel'ng a new drive so difficult? 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: Thu, 29 Mar 2007 22:07:22 -0000 On 29/03/2007 6:41 AM, Kris Kennaway wrote: > On Wed, Mar 28, 2007 at 05:26:49PM -0300, Marc G. Fournier wrote: >> Just bought a new WD SATA drive: WDC WD5000YS-01MPB1 09.02E09 >> >> Tried to disklabel it, and it gives me all kinds of warnings when I look at it >> after running the disklabel: >> >> >> ganymede# bsdlabel -w ad4s1 auto >> ganymede# bsdlabel ad4s1c >> # /dev/ad4s1c: >> 8 partitions: >> # size offset fstype [fsize bsize bps/cpg] >> a: 976767986 79 unused 0 0 >> c: 976768002 63 unused 0 0 # "raw" part, don't >> edit >> partition a: partition extends past end of unit >> partition c: partition extends past end of unit >> bsdlabel: partition c doesn't start at 0! >> bsdlabel: An incorrect partition c may cause problems for standard system >> utilities >> >> Even if I try to use /stand/sysinstall to do the fdisk, the end result has >> 'issues' ... >> >> So, what is the generally accepted method of label'ng a new drive? :( > > I learned a useful trick the other day: you can use abbreviations like > "1g", also '*' to mean "automatically calculate". See the manpage. This timely thread came as I was experimenting with disklabel, and I noticed in the man page it says this: > offset The offset of the start of the partition from the beginning of > the drive in sectors, or * to have bsdlabel calculate the correct > offset to use (the end of the previous partition plus one, ignor- > ing partition `c'. For partition `c', * will be interpreted as > an offset of 0. The first partition should start at offset 16, > because the first 16 sectors are reserved for metadata. When I tried using "16" as the offset for my 'a' partition, I could no longer user "*" on my last partition to make it auto-size... disklabel then sized the partition so it went past the end of the disk. Presumably it's not taking into account the starting offset when it does this (gm0 is a 3gb gmirror device, with a single slice created on it using fdisk): $ bsdlabel -R /dev/mirror/gm0s1 /dev/stdin 8 partitions: a: 2097152 16 4.2BSD b: 102400 * swap c: * 0 unused d: 102400 * 4.2BSD e: * * 4.2BSD partition e: partition extends past end of unit However if I change the 'a' partition offset to 'e', it works: $ bsdlabel -R /dev/mirror/gm0s1 /dev/stdin 8 partitions: a: 2097152 0 4.2BSD b: 102400 * swap c: * 0 unused d: 102400 * 4.2BSD e: * * 4.2BSD $ disklabel /dev/mirror/gm0s1 # /dev/mirror/gm0s1: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 2097152 0 4.2BSD 0 0 0 b: 102400 2097152 swap c: 6281352 0 unused 0 0 # "raw" d: 102400 2199552 4.2BSD 0 0 0 e: 3979400 2301952 4.2BSD 0 0 0 Is it important to use 16 as the offset still, or is this a historical piece of information that is no longer relevant? Or is this is a bug in disklabel that should be fixed? --Antony