From owner-cvs-src@FreeBSD.ORG Fri Apr 16 08:31:56 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C9AA516A4CE; Fri, 16 Apr 2004 08:31:56 -0700 (PDT) Received: from mailout1.pacific.net.au (mailout1.pacific.net.au [61.8.0.84]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0529D43D46; Fri, 16 Apr 2004 08:31:54 -0700 (PDT) (envelope-from bde@zeta.org.au) Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86])i3GFVq4u029751; Sat, 17 Apr 2004 01:31:52 +1000 Received: from gamplex.bde.org (katana.zip.com.au [61.8.7.246]) i3GFVoI2015756; Sat, 17 Apr 2004 01:31:51 +1000 Date: Sat, 17 Apr 2004 01:31:49 +1000 (EST) From: Bruce Evans X-X-Sender: bde@gamplex.bde.org To: "David O'Brien" In-Reply-To: <20040416150742.GA16010@dragon.nuxi.com> Message-ID: <20040417011735.N14463@gamplex.bde.org> References: <200404130258.i3D2w7WC034439@repoman.freebsd.org> <20040416150742.GA16010@dragon.nuxi.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: Brian Feldman cc: src-committers@freebsd.org cc: cvs-all@freebsd.org cc: cvs-src@freebsd.org Subject: Re: cvs commit: src/sbin/dump dump.8 dump.h main.c tape.csrc/sbin/restore extern.h main.c restore.8 tape.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Apr 2004 15:31:57 -0000 On Fri, 16 Apr 2004, David O'Brien wrote: > On Mon, Apr 12, 2004 at 07:58:07PM -0700, Brian Feldman wrote: > > green 2004/04/12 19:58:07 PDT > > > > FreeBSD src repository > > > > Modified files: > > sbin/dump dump.8 dump.h main.c tape.c > > sbin/restore extern.h main.c restore.8 tape.c > > Log: > > Add -P arguments for dump(8) and restore(8) which allow the user to > > use backup methods other than files and tapes. The -P argument is > > a normal sh(1) pipeline with either $DUMP_VOLUME or $RESTORE_VOLUME > > defined in the environment, respectively. > > Why do you need an option for this? Can't you just use 'dump ... |' and > '... | restore'? A simple pipeline can't handle media-change stuff well. Minix has a "vol" command which handles media changes for piped data. The media size is fixed and specified on the command line (typical usage was "tar ... | vol 360 /dev/fd0" for 360K floppies (remember them?)). This could be generalized to take a -P option much like dump now does (tar ... | vol -P ...). I don't know if dump needs to know more about media boundaries than can be handled in this way. A robust backup format would involve metadata at the start of each volume, and that is another thing that can'r be handled by a simple pipeline with the main generator of the data not knowing that it is writing to a fake large volume that actually consists of multiple volumes concatenated externally. Bruce