From owner-freebsd-stable Tue Apr 27 21:14:54 1999 Delivered-To: freebsd-stable@freebsd.org Received: from guru.phone.net (guru.phone.net [209.157.82.120]) by hub.freebsd.org (Postfix) with SMTP id 97B4714E34 for ; Tue, 27 Apr 1999 21:14:52 -0700 (PDT) (envelope-from mwm@phone.net) Received: (qmail 12564 invoked by uid 100); 28 Apr 1999 04:14:51 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 28 Apr 1999 04:14:51 -0000 Date: Tue, 27 Apr 1999 21:14:51 -0700 (PDT) From: Mike Meyer To: freebsd-stable@freebsd.org Subject: Re: Does tar do sparse files these days In-Reply-To: <199904280102.VAA02170@mailfw1.ford.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 28 Apr 1999, Brian O'Connor. (CF583173) HO 2nd Floor wrote: > Hello > This is not specific to freebsd-stable, but you guys are more than likely > to know the answer. > > In the dim dark days of yore(90-91) I was advised not to do full backups using tar. > There were problems with sparse files, and device files etc. > > Since then I've used dump or its varients on various implementations of unix > when I've wanted a trust worthy backup. At Ford they use a commercial network > backup product called Netbackup (from veritas) it uses tar format for its > backups, so much so that you can recover a netbackup tape using tar -xvf .... > > This suprised the hell out me, has tar format changed in the last few years? > or was mistaken all along? Yes to both. I believe tar has always handled sparse files - but not very well, and you didn't always get back exactly the same "holes". The format has been extended since then so that it handles things better. Veritas could well have extended this process even further.