From owner-freebsd-questions@FreeBSD.ORG Mon Nov 5 02:37:44 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 3A331D9D for ; Mon, 5 Nov 2012 02:37:44 +0000 (UTC) (envelope-from rfg@tristatelogic.com) Received: from outgoing.tristatelogic.com (segfault.tristatelogic.com [69.62.255.118]) by mx1.freebsd.org (Postfix) with ESMTP id 0F5448FC14 for ; Mon, 5 Nov 2012 02:37:43 +0000 (UTC) Received: from segfault-nmh-helo.tristatelogic.com (localhost [127.0.0.1]) by segfault.tristatelogic.com (Postfix) with ESMTP id 29F0C50821 for ; Sun, 4 Nov 2012 18:37:43 -0800 (PST) To: freebsd-questions@freebsd.org Subject: Re: Questions about dump/restore to/from DVD media In-Reply-To: <20121105021817.fc5bff1b.freebsd@edvax.de> Date: Sun, 04 Nov 2012 18:37:43 -0800 Message-ID: <21628.1352083063@tristatelogic.com> From: "Ronald F. Guilmette" X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Nov 2012 02:37:44 -0000 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. >The command "growisofs -Z /dev/cd0=" will record the file "like >an image" to the media. In most cases, that would be an ISO-9660 file >system, like "growisofs -Z /dev/cd0=stuff.iso" (with a premastered >file stuff.iso). In _this_ case, the input data is read directly from >file descriptor 0, stdin. Whatever appears there, it will be written >to the media. Ah! OK. I see now. Thank you. >> If so, how would I do this? Would a command >> such as the following work? >> >> /sbin/dump -0u -L -C16 -B4589840 -P 'dd of=/dev/acd0 bs=2048' /u >> >> If not, why not? > >As far as I know, direct device access for writing does not work here. Yes, apparently not. Bit I _did_ just find something rather interesting in this context. Look at this: http://sg.danny.cz/sg/ddpt.html I have no idea why it isn't already in the ports tree. I'll probably try it out and see if it works. >> 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. >> 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. (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.)