From owner-freebsd-stable@FreeBSD.ORG Tue Nov 23 19:14:39 2010 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8BBE710656AE for ; Tue, 23 Nov 2010 19:14:39 +0000 (UTC) (envelope-from mike@sentex.net) Received: from smarthost1.sentex.ca (smarthost1-6.sentex.ca [IPv6:2607:f3e0:0:1::12]) by mx1.freebsd.org (Postfix) with ESMTP id 2773D8FC1C for ; Tue, 23 Nov 2010 19:14:39 +0000 (UTC) Received: from [IPv6:2607:f3e0:0:4:49a2:dbc6:564:65a6] ([IPv6:2607:f3e0:0:4:49a2:dbc6:564:65a6]) by smarthost1.sentex.ca (8.14.4/8.14.4) with ESMTP id oANJESDR047726 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Tue, 23 Nov 2010 14:14:29 -0500 (EST) (envelope-from mike@sentex.net) Message-ID: <4CEC128F.7070903@sentex.net> Date: Tue, 23 Nov 2010 14:14:23 -0500 From: Mike Tancsa User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.12) Gecko/20101027 Thunderbird/3.1.6 MIME-Version: 1.0 To: David Magda References: <20101122113541.GA74719@johnny.reilly.home> <4CEA8BA6.7080009@kc8onw.net> <20101122221350.GA81098@johnny.reilly.home> <9F5A7E06-9646-4D3B-BF72-273B713043DE@ee.ryerson.ca> In-Reply-To: <9F5A7E06-9646-4D3B-BF72-273B713043DE@ee.ryerson.ca> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.67 on IPv6:2607:f3e0:0:1::12 Cc: stable@freebsd.org Subject: Re: ZFS backups: retrieving a few files? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Nov 2010 19:14:39 -0000 On 11/22/2010 8:29 PM, David Magda wrote: > On Nov 22, 2010, at 17:13, Andrew Reilly wrote: > >>> The currently accepted practice is to create a ZFS file system on the >>> backup drive and just keep sending incremental snapshots to it. As long >>> as the backup drive and host system have a snapshot in common you can do >>> incremental transfers. This way you only have to keep the most recent >>> snapshot on the main system and can keep as many as you have space for >>> on the backup drive. You also have direct access to any backed up >>> version of every file. >> >> That sounds like a very cool notion. Not unlike the >> time-machine scheme. Interesting how different capabilities >> require going back and re-thinking the problem, rather than just >> trying to implement the old solution with the new tools. > > As noted, saving the output of "zfs send" isn't very useful and > generally not recommended as a backup mechanism. It's come up quite > often on Sun/Oracle's zfs-discuss list: > > http://www.google.com/search?q=zfs+send/receive+as+backup+tool > > In addition to regular snapshots, also make sure to have an offline > backup of some kind (tar, Networker, NetBackup, Amanada, etc.). Errors > can propagate to online copies / backups, and if an intruder can > penetrate your primary system, there's a good chance they can get to the > secondary copy of your data; penetrating a tape on a shelf over the > network would be much more challenging. :) I am still trying to figure out the best way to do zfs backups locally here for rollbacks as well as DR. I was looking at some of the techniques at http://www.cuddletech.com/blog/pivot/entry.php?id=984 But thats outdated ? WRT errors in the file, perhaps PAR* tools can overcome some of these issues if you are dumping to a file on tape */usr/ports/archivers/par2cmdline ---Mike