From owner-freebsd-stable@FreeBSD.ORG Fri Jan 12 07:07:07 2007 Return-Path: X-Original-To: stable@FreeBSD.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id AEBA316A407 for ; Fri, 12 Jan 2007 07:07:07 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from smtpout.mac.com (smtpout.mac.com [17.250.248.176]) by mx1.freebsd.org (Postfix) with ESMTP id 9834B13C44C for ; Fri, 12 Jan 2007 07:07:07 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from mac.com (smtpin04-en2 [10.13.10.149]) by smtpout.mac.com (Xserve/8.12.11/smtpout06/MantshX 4.0) with ESMTP id l0C6opBV022829; Thu, 11 Jan 2007 22:50:51 -0800 (PST) Received: from [172.23.8.4] (nat-service4.juniper.net [66.129.225.151]) (authenticated bits=0) by mac.com (Xserve/smtpin04/MantshX 4.0) with ESMTP id l0C6oidH026003 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Thu, 11 Jan 2007 22:50:46 -0800 (PST) In-Reply-To: References: <45A5FD8A.6080409@svcolo.com> <2918081F-D376-410B-B6FD-42BDD3323575@svcolo.com> <20070111213444.GB17185@zone3000.net> Mime-Version: 1.0 (Apple Message framework v752.3) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Marcel Moolenaar Date: Thu, 11 Jan 2007 22:49:38 -0800 To: Jo Rhett X-Mailer: Apple Mail (2.752.3) X-Brightmail-Tracker: AAAAAA== X-Brightmail-scanned: yes Cc: stable@FreeBSD.org, Nikolay Pavlov Subject: Re: 2.4TB disk - MBR and GPT coexist? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Jan 2007 07:07:07 -0000 On Jan 11, 2007, at 1:56 PM, Jo Rhett wrote: > Since we're going to be stuck with old BIOSes for a long time after > 2TB is a cheap disk drive at [store], is anyone considering doing > the work to make GPT co-exist with an MBR block? It is already possible for them to coexist. It's not uncommon in the industry to use MBR partitions even though the disk has GPT. The point is that you need to tools to avoid making a mess. Ideally you want the MBR partitions mirrored by the GPT so that the kernel only has to deal with GPT. The BIOS will use the MBR to boot. The gpt(8) tool can actually be used to set this up. You partition the disk with fdisk, but only for the boot partition. Then you run gpt(8) to migrate the MBR into a GPT, specifying the -s option so that you get a single GPT partition overlapping the MBR slice. After that you restore the MBR partition. Now you can use GPT to define a big partition. The kernel will use GPT and since you used -s when you migrate the MBR, the kernel will create device nodes with the same name as it would for the MBR partitions... -- Marcel Moolenaar xcllnt@mac.com