From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1OEjFu-0003BZ-G2 for mharc-grub-devel@gnu.org; Wed, 19 May 2010 09:24:14 -0400 Received: from [140.186.70.92] (port=53499 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OEjFo-00039L-B0 for grub-devel@gnu.org; Wed, 19 May 2010 09:24:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OEjFl-0003oK-Ns for grub-devel@gnu.org; Wed, 19 May 2010 09:24:08 -0400 Received: from mail.gmx.net ([213.165.64.20]:54725) by eggs.gnu.org with smtp (Exim 4.69) (envelope-from ) id 1OEjFl-0003ng-Bk for grub-devel@gnu.org; Wed, 19 May 2010 09:24:05 -0400 Received: (qmail invoked by alias); 19 May 2010 13:24:02 -0000 Received: from 165.126.46.212.adsl.ncore.de (HELO 192.168.2.69) [212.46.126.165] by mail.gmx.net (mp004) with SMTP; 19 May 2010 15:24:02 +0200 X-Authenticated: #2145628 X-Provags-ID: V01U2FsdGVkX19bqc5Tec5b/Yt8sCPYUKzyePn5Gms11RaO6uoynr vV50gAbIXidnsi Date: Wed, 19 May 2010 15:23:26 +0200 From: "Thomas Schmitt" To: grub-devel@gnu.org References: <20100519121335.GU21862@riva.ucam.org> In-Reply-To: <20100519121335.GU21862@riva.ucam.org> Message-Id: <106265329817470@192.168.2.69> X-Y-GMX-Trusted: 0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Subject: Re: Migrations to xorriso 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: Wed, 19 May 2010 13:24:13 -0000 Hi, > > - Option --diet saves about 400 kB of image > > size without losing much benefit. > If it doesn't lose much, > why would it not be the default? Maybe one should revert the default and offer an option --multi-session-toc instead ? > Or, put another way, why would > somebody want to turn this option off? I could want a bootable multi-session backup on USB stick with the opportunity to mount the backup state of two weeks ago. For that i'd start with a rescue system created by grub-mkrescue, add my base backup as second session and daily updates as further sessions. The extra 64 kB to 126 kB make sure that the older sessions of a multi-session ISO image can be detected and mounted. Useful with incremental backups on regular files, USB sticks, DVD+RW or BD-RE media. But not so much of interest with a single session rescue image. Without this extra space one can still add new sessions but will always see the youngest one as the only session of the image. (growisofs does it that way.) If the first session ends up on sequential media (CD-R[W], DVD-R, DVD+R, BD-R) then further multi-session will be managed by the drive anyway. > Useless use of cat. Not in this case. xorriso calls fstat(2) to determine the semantics of the given output file. Option -o "${output_image}" or a redirection by >"${output_image}" would both reveil type S_IFREG. But for the diet case i want S_ISCHR or S_IFIFO so that the output "media" appears as sequential rather than as overwriteable. Have a nice day :) Thomas