From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f193.google.com ([209.85.216.193]:44545 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752212AbdJLBDf (ORCPT ); Wed, 11 Oct 2017 21:03:35 -0400 Received: by mail-qt0-f193.google.com with SMTP id 8so10702677qtv.1 for ; Wed, 11 Oct 2017 18:03:35 -0700 (PDT) Received: from lubh.lubhome ([179.34.192.80]) by smtp.gmail.com with ESMTPSA id 36sm8986227qtr.42.2017.10.11.18.03.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Oct 2017 18:03:34 -0700 (PDT) Date: Wed, 11 Oct 2017 22:03:31 -0300 From: Luciano ES Subject: Re: Questions about backups with XFS Message-ID: <20171011220331.4af6308c@lubh.lubhome> In-Reply-To: <20171009105701.GL3666@dastard> References: <20171007114343.3bd42f98@lubh.lubhome> <20171009084451.yj7fvv6wqra27vuo@hades.localdomain> <20171009105701.GL3666@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: linux-xfs@vger.kernel.org On Mon, 9 Oct 2017 21:57:01 +1100, Dave Chinner wrote: > On Mon, Oct 09, 2017 at 10:44:51AM +0200, Carlos Maiolino wrote: > > Hi. > > > > > > On Sat, Oct 07, 2017 at 02:43:43PM +0000, Luciano ES wrote: > > > I have a few questions and I was torn between asking them > > > separately and putting them all in one message. I decided for the > > > latter and I hope this is not a problem. > > > > > > Once upon a time, many many years ago, I used to make backup > > > copies of my file systems with the 'cp -aux' command, including > > > my live root file system. Luckily, I never had to restore any > > > live root file system from those backups. They probably would > > > never have worked. > > > > > > Later on, someone taught me to do it like this: > > > > > > find /source -xdev -print0 | cpio -pa0V /target > > > > > > That command is supposed to copy everything, including special > > > files (not really sure which) that mere cp or even rsync would > > > not copy. I actually used that approach several times, including > > > restoration, and it always worked. > > > > > > For some reason, I stopped making backups of my live root file > > > system, but I still backup other partitions with rsync, always > > > with the --delete-before parameter, so the target is always an > > > exact copy of the source. > > > > > > I have been using XFS for a few years and thought that maybe it's > > > time I enjoyed all the benefits of the XFS management tools. > > > However, I am uncertain about things I haven't been able to find > > > in the documentation or even on the Web: > > > > > > Question #1: > > > Does xfsdump really copy EVERYTHING? Can I backup a full live > > > root file system with it and expect a restored copy to boot and > > > run uneventfully? Or should I rather do a 'hard' image with > > > xfs_copy? > > > > xfs_copy must only be used an unmounted filesystem (or read-only, > > frozen, etc), so, unless you want to freeze/unmount your FS > > everytime you do a xfs_copy, then xfs_copy is not what you are > > looking for > > I'll just say this: xfs_copy is not a backup tool. It's a filesystem > image replication tool designed for fast, efficient 1-to-many > duplication of a golden filesystem image to multiple drives, such as > is done in manufacturing lines.... So xfs_copy is not a backup tool, and what does that mean in the context of my backup plan? Why can't I or should I not use it as a backup tool? If it is a replication tool, well, it replicates, it creates a copy that can be used to recreate a file system in a very specific state. Is there any technical impediment to the use I plan to make of it? -- Luciano ES >>