From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.webfaction.com ([74.55.86.74]:33943 "EHLO smtp.webfaction.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030448AbaGRRzm (ORCPT ); Fri, 18 Jul 2014 13:55:42 -0400 Received: from [172.17.0.4] (unknown [76.14.35.15]) by smtp.webfaction.com (Postfix) with ESMTP id 6386066EC3D2 for ; Fri, 18 Jul 2014 17:31:20 +0000 (UTC) Message-ID: <53C959FE.7070808@glidelink.net> Date: Fri, 18 Jul 2014 10:31:42 -0700 From: Daniel Mizyrycki Reply-To: mzdaniel@glidelink.net MIME-Version: 1.0 CC: linux-btrfs@vger.kernel.org Subject: Re: Questions on incremental backups References: <1405627978.2630.39.camel@s-Air> <1405688218.3085.16.camel@s-Air> <1483007.OXNgJN24dh@xev> In-Reply-To: <1483007.OXNgJN24dh@xev> Content-Type: text/plain; charset=ISO-8859-1; format=flowed To: unlisted-recipients:; (no To-header on input) Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 07/18/14 06:40, Russell Coker wrote: >>> Displaying backups is an issue of backup software. It is above the >>> level that BTRFS development touches. While people here can probably >>> offer generic advice on backup software it's not the topic of the >>> list. >> >> As said, I don't mind developing the software. But, is the required >> information easily available? Is there a way to get a diff, something >> like a list of changed/added/removed files between snapshots? > > Your usual diff utility will do it. I guess you could parse the output of > btrfs send. Following this thought, one step closer in getting a text diff can be to use fardump. It takes a btrfs send binary stream and outputs the send instructions in plaintext. (https://kernel.googlesource.com/pub/scm/linux/kernel/git/arne/far-progs). It certainly would be awesome if btrfs-progs could have an extra parameter to just generate the list of changed/added/removed files between snapshots as all the needed infrastructure is already in place. > >> And, finally, nobody has mentioned on the possibility of merging >> multiple snapshots into a single snapshot. Would this be possible, to >> create a snapshot that contains the most recent version of each file >> present across all of the snapshots (including files which may be >> present in only one of the snapshots)? > > There is no btrfs functionality for that. But I'm sure you could do something > with standard Unix utilities and copying files around. Sure, but the management of data deduplication is left to the user (presumably using cp --reflink) which is not trivial. Does anybody knows how safe it is to use duperemove or bedup? Any recommendations on how to effectively deduplicate btrfs at this point?