From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1ONpr4-0008Fi-Vs for mharc-grub-devel@gnu.org; Sun, 13 Jun 2010 12:16:14 -0400 Received: from [140.186.70.92] (port=48075 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ONpr1-0008DX-Pd for grub-devel@gnu.org; Sun, 13 Jun 2010 12:16:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1ONpr0-0002h3-I9 for grub-devel@gnu.org; Sun, 13 Jun 2010 12:16:11 -0400 Received: from mail-ww0-f41.google.com ([74.125.82.41]:35532) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1ONpr0-0002gu-DW for grub-devel@gnu.org; Sun, 13 Jun 2010 12:16:10 -0400 Received: by wwb34 with SMTP id 34so3186573wwb.0 for ; Sun, 13 Jun 2010 09:16:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=C+BMIPjS2nFLT/SFRbSspbz/VLHdzrFqRNlFTatQUuU=; b=UqPuowUSapO0qYaREemUUreM7yA4P+wMF1jeBLjEKpZDxqe8PIq0V9V9gZnfAxT93p Yu+gAK0tROvG/U0VqWmH+p9QweZzH4xErWzTdo58Pd9ZI3UN7i+gSEh1zRd9+xzeZUGZ SA0EYbIJ/miIwDJ52c5I9ycPrupDuRXJ42Y08= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; b=XB1KI4zb8PXEvDDuHFmk/+pcCTwmJPc/IuI8bawVgkqOr6MsiNDGZQPnWtxen19/D+ 6envvyFH3Xt1ZKvN8tCz/60w63F0qRv6h6uUPCAomQmqo1pNDT0XJ4lmAVnhkzO3wcfT jh8h36m/3Ph9wcpk26C4rKvRoCRbUKQg6gZiQ= Received: by 10.227.152.76 with SMTP id f12mr4502393wbw.54.1276445768797; Sun, 13 Jun 2010 09:16:08 -0700 (PDT) Received: from [192.168.1.50] ([88.160.112.182]) by mx.google.com with ESMTPS id b17sm28910124wbd.7.2010.06.13.09.16.08 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 13 Jun 2010 09:16:08 -0700 (PDT) Message-ID: <4C15044D.9050608@gmail.com> Date: Sun, 13 Jun 2010 18:16:13 +0200 From: =?UTF-8?B?R3LDqWdvaXJlIFN1dHJl?= User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100515 Icedove/3.0.4 MIME-Version: 1.0 To: The development of GNU GRUB References: <4C0BE2C7.4020407@gmail.com> <4C0D5AAE.6070504@gmail.com> <4C13B6A8.7060102@gmail.com> <4C13C33B.4090302@gmail.com> In-Reply-To: <4C13C33B.4090302@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Subject: Re: Which partitioning schemes should be supported by GRUB? X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Jun 2010 16:16:12 -0000 On 06/12/2010 07:26 PM, Vladimir 'φ-coder/phcoder' Serbinenko wrote: > Any "hybrid" cofiguration fails the criteria of non confusability. I was assuming the new partition notation. The old notation is clearly ambiguous when there are multiple partmaps, and AFAIR the new notation was introduced precisely to solve that problem: http://lists.gnu.org/archive/html/grub-devel/2010-01/msg00320.html By the way, the old notation is worse than ambiguous when there are multiple partmaps: the meaning of partition identifiers depends on the partmap modules that are loaded, and on the order in which they are loaded. > Let's consider a following situation: - I format disk with scheme A > and partitions A1, A2, A3 - I get bored and reformat with scheme B > and partitios B1, B2, B3, B4. When I did this filesystem on A2 may > stay intact - I use grub which supposes that it'shybrid system A+B > and save_env's to A2 since it's a valid partition on valid > filesystem. But by a bad luck save_env overlaps with superblock of B3 > which becomes corrupted. If you save_env with -f then, with new notation, you know that you are using the old scheme A. If you didn't use -f, then it means that grub modules were installed into A2 and survived the reformat, but then, how could GRUB know that A is obsolete? IMHO corrupting the superblock of B3 is acceptable in that case. An alternative would be to check that partitions do not overlap (with the exception of identical partitions). But even this would work only if the partmap module for B was loaded, which is likely not the case (as grub was installed at the time A was used). > And currently grub isn't changed to new partition notation > completely. E.g. during startup prefix is calculated with old syntax > and confusing A+B with either A or B is likely to make user drop into > rescue shell Is someone working on making the startup prefix use the new notation? Grégoire