From owner-freebsd-questions@FreeBSD.ORG Mon Nov 5 02:52:36 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 54863308 for ; Mon, 5 Nov 2012 02:52:36 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mx02.qsc.de (mx02.qsc.de [213.148.130.14]) by mx1.freebsd.org (Postfix) with ESMTP id 0D92B8FC14 for ; Mon, 5 Nov 2012 02:52:35 +0000 (UTC) Received: from r56.edvax.de (port-92-195-8-72.dynamic.qsc.de [92.195.8.72]) by mx02.qsc.de (Postfix) with ESMTP id 9747224042; Mon, 5 Nov 2012 03:52:34 +0100 (CET) Received: from r56.edvax.de (localhost [127.0.0.1]) by r56.edvax.de (8.14.5/8.14.5) with SMTP id qA52qXuv002700; Mon, 5 Nov 2012 03:52:33 +0100 (CET) (envelope-from freebsd@edvax.de) Date: Mon, 5 Nov 2012 03:52:33 +0100 From: Polytropon To: "Ronald F. Guilmette" Subject: Re: Questions about dump/restore to/from DVD media Message-Id: <20121105035233.e3c4ae8a.freebsd@edvax.de> In-Reply-To: <21628.1352083063@tristatelogic.com> References: <20121105021817.fc5bff1b.freebsd@edvax.de> <21628.1352083063@tristatelogic.com> Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: Polytropon List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Nov 2012 02:52:36 -0000 On Sun, 04 Nov 2012 18:37:43 -0800, Ronald F. Guilmette wrote: > > In message <20121105021817.fc5bff1b.freebsd@edvax.de>, > Polytropon wrote: > > >> I would like to make this backup to a _minimal_ number of DVD+R disks. > > > >If you think you can add compression to your files (if it makes > >sense), it should be incorporated to the command. > > Yes. There really ought to be a -z option integrated into both dump and > restore commands. Depending on _what_ kind of compression (gzip, bzip2, 7zip, xz etc.) there might be many of them. If utilizing the capabilities of libarchive is possible, it would be a nice option. > >> Another issue is that I most definitely want to use an absolute minimum... > > > >Taking the initial approach of > > > >/sbin/dump -0u -L -C16 -B4589840 -P 'growisofs -Z /dev/cd0=/dev/fd/0' /u > > > >it could be something like this: > > > >/sbin/dump -0u -L -C16 -B4589840 -P 'gzip | growisofs -Z /dev/cd0=-' /u > > Yes. I see. That makes sense. > > But as I said (above) to make this really work right, dump & restore really > need to have -z options, and do the zipping/unzipping internally. Only > if this were available could dump properly deal with end-of-media on any > given output volume, I think. The problem is that delegating compression to a "sub-task" would imply that dump cannot precisely adjust its output to match the media size (as the limit is now defined by how good the compression works). Instead an additional step would be required to make sure that a new media for the _compressed_ data stream is requested when it exceeds a certain limit. Additionally restore would have to use a comparable method of "chaining" the multiple volumes, as it requires operator attention and action. > >> Lastly, I want to make a backup of one entire _system_... not just one of > >> the several partitions that compose that system. How exactly can I do > >> this? > > > >At least not with dump. The dump utility operates on file systems, > >this means "it takes partitions as input". Whatever is _one_ partition > >can be processed "per step". > > Well, this is entirely sub-optimal. It depends on how you did layout your system. Using dump + restore means to operate on partitions. Make the system one partition - deal with one partition. Make many partitions - need to deal with them individually. > (I hate to say it, because in general I loath & despise Windows, but even > Windows has a built-in facility for making a single backup of an _entire_ > system, and in a single step, *and*, I presume in a space-efficient manner.) That would be a task for dd. :-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...