From owner-freebsd-stable@FreeBSD.ORG Sun Feb 19 07:09:07 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E61BF1065670; Sun, 19 Feb 2012 07:09:07 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-vx0-f182.google.com (mail-vx0-f182.google.com [209.85.220.182]) by mx1.freebsd.org (Postfix) with ESMTP id 81BA48FC13; Sun, 19 Feb 2012 07:09:07 +0000 (UTC) Received: by vcmm1 with SMTP id m1so4427985vcm.13 for ; Sat, 18 Feb 2012 23:09:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=ve3gqBE7uUBBSbOEc7tzg3avshdZ0ykEJdFvXIsZysY=; b=p8PxCWkgjo+e8z9q05sp+nQA1O/Twqmc6KFPPs+11QOwuUFarqohqIFEsXkhAyssjS RJkRTTwIMDycbA3+Fvd0GyzvNwajBdeGUTLUlOeVBKl5aYDZqvCcS6q0sQXhIcUSN27T vXJNbxUvHHGH9DM4VraiIeusd+K4nGlPqDSOo= MIME-Version: 1.0 Received: by 10.220.141.133 with SMTP id m5mr6907244vcu.67.1329635346678; Sat, 18 Feb 2012 23:09:06 -0800 (PST) Received: by 10.220.192.135 with HTTP; Sat, 18 Feb 2012 23:09:06 -0800 (PST) Received: by 10.220.192.135 with HTTP; Sat, 18 Feb 2012 23:09:06 -0800 (PST) In-Reply-To: References: <20120217.160430.406937514120319292.hrs@allbsd.org> <4F3E3000.9000206@FreeBSD.org> <20120217.232843.2212672671663755444.hrs@allbsd.org> <4F3EC8DD.6040500@FreeBSD.org> Date: Sat, 18 Feb 2012 23:09:06 -0800 Message-ID: From: Freddie Cash To: Kevin Oberman Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: wblock@wonkity.com, freebsd-stable@freebsd.org, 000.fbsd@quip.cz, Andriy Gapon , mandrews@bit0.com, freebsd@jdc.parodius.com Subject: Re: New BSD Installer 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: Sun, 19 Feb 2012 07:09:08 -0000 If you're mirroring the disk with gmirror, how are you dual-booting the disk? This discussion is about using gmirror to mirror two entire disks, and then use GPT to partition the mirror device. Dual-booting has no bearing on that, as gmirror is a FreeBSD-only technology. Cheers, Freddie Cash fjwcash@gmail.com On Feb 18, 2012 10:37 PM, "Kevin Oberman" wrote: > On Fri, Feb 17, 2012 at 1:50 PM, Freddie Cash wrote: > > On Fri, Feb 17, 2012 at 1:38 PM, Andriy Gapon wrote: > >> And just in case: > >> Unified Extensible Firmware Interface Specification Version 2.3.1, > Errata A > >> September 7, 2011 says: > >> [snip] > >>> Two GPT Header structures are stored on the device: the primary and the > >>> backup. The primary GPT Header must be located in LBA 1 (i.e., the > second > >>> logical block), and the backup GPT Header must be located in the last > LBA > >>> of the device. > >> > >> I can not see any ambiguity or openness to interpretation in this > paragraph. > > > > Unless it's specified somewhere else (which is possible), in this > > paragraph, "device" does not necessarily mean "physical disk". "Last > > LBA of the device" could be interpreted as "last LBA of the GEOM > > provider". > > > > The beauty of GEOM is that "device" is whatever logical mapping it > provides. > > > > After all, LBAs are logical addresses (it's right there in the name!), > > not hardwired physical sector addresses. ;) If they were hardwired, > > then how would internal sector remapping work? ;) > > Please remember that some disks are dual-boot. FreeBSD may understand > geom has the backup one block from the last LBA on the disk, but no > other OS is likely to do so. > > Unless I am missing something, this should be a non-starter. Totally > unacceptable. The backup belongs in the last and only in the last LBA > on the physical disk. > -- > R. Kevin Oberman, Network Engineer > E-mail: kob6558@gmail.com >