From owner-freebsd-geom@FreeBSD.ORG Fri Apr 20 17:36:35 2007 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 605C216A407; Fri, 20 Apr 2007 17:36:35 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from smtpout.mac.com (smtpout.mac.com [17.250.248.183]) by mx1.freebsd.org (Postfix) with ESMTP id 4877A13C457; Fri, 20 Apr 2007 17:36:35 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from mac.com (smtpin08-en2 [10.13.10.153]) by smtpout.mac.com (Xserve/smtpout13/MantshX 4.0) with ESMTP id l3KHaUNR021077; Fri, 20 Apr 2007 10:36:30 -0700 (PDT) Received: from [172.24.104.161] (natint3.juniper.net [66.129.224.36]) (authenticated bits=0) by mac.com (Xserve/smtpin08/MantshX 4.0) with ESMTP id l3KHaSeg003854 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Fri, 20 Apr 2007 10:36:29 -0700 (PDT) In-Reply-To: <86wt076k7u.fsf@dwp.des.no> References: <86wt076k7u.fsf@dwp.des.no> Mime-Version: 1.0 (Apple Message framework v752.3) Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed Message-Id: <619464E1-1CB4-4CFC-9ECF-7FC90DC24A20@mac.com> Content-Transfer-Encoding: quoted-printable From: Marcel Moolenaar Date: Fri, 20 Apr 2007 10:35:28 -0700 To: =?ISO-8859-1?Q?Dag-Erling_Sm=F8rgrav?= X-Mailer: Apple Mail (2.752.3) X-Brightmail-Tracker: AAAAAA== X-Brightmail-scanned: yes Cc: freebsd-current@freebsd.org, Ivan Voras , freebsd-geom@freebsd.org Subject: Re: GPT as default? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Apr 2007 17:36:35 -0000 On Apr 20, 2007, at 10:15 AM, Dag-Erling Sm=F8rgrav wrote: > Ivan Voras writes: >> Many systems (including MacOS X and Solaris) are moving to GPT >> partitions (http://en.wikipedia.org/wiki/GUID_Partition_Table), =20 >> mostly >> because they don't have the above limitations. My proposal is that we >> deprecate BSD labels and move to GPT in 7.0 (or more correctly, if =20= >> the >> stars were to be benevolent on us, on the new systems that are >> installed by the new GPT-aware installer :) ). > > Not unless geom_gpt receives considerable attention. It receives attention. > Currently, it is not even possible to list the GPT, let alone create > new partitions, if one of the partitions is open. GPT can not be the > default partitioning scheme until this is addressed. You can list with the -r option. You cannot create unless you allow foot-shooting in GEOM (i.e. set kern.geom.debugflags=3D16). The latter a known side-effect of GEOM and has nothing to do with GPT itself. Anyway: The new G_PART class is there to fix it... >> The second is more serious: FreeBSD boot code cannot boot from a GPT >> partition. >> >> Part of the problem is that GPT uses GUIDs for distinguishing >> partition types, so the current code that recognizes various =20 >> partition >> types (Linux, FreeBSD, NTFS - the famous "F1" prompt) may need to be >> thrown out since each GUID is 16 bytes long and AFAIK there's only >> about 300 bytes in the MBR for the boot code. > > DOS partitions normally start on a cylinder boundary, even though > cylinders no longer mean anything. This means there is plenty of > space for code and data between the MBR and the first partition. > > I don't know if this is also the case with GPT. It isn't. If disk space is needed, one can always create a partition for it. There's no need to stuff things in anonymous sectors. --=20 Marcel Moolenaar xcllnt@mac.com