From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mo4-p00-ob.smtp.rzone.de ([81.169.146.220]:30900 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752216AbaCMTTJ (ORCPT ); Thu, 13 Mar 2014 15:19:09 -0400 Received: from fuchsia.localnet (p5DE8FFB9.dip0.t-ipconnect.de [93.232.255.185]) by smtp.strato.de (RZmta 32.27 DYNA|AUTH) with ESMTPSA id R076e3q2DJCi4RI (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) for ; Thu, 13 Mar 2014 20:12:44 +0100 (CET) From: Michael Schuerig To: linux-btrfs@vger.kernel.org Subject: Incremental backup for a raid1 Date: Thu, 13 Mar 2014 20:12:44 +0100 Message-ID: <1564384.fRV1HUkfCq@fuchsia> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-btrfs-owner@vger.kernel.org List-ID: My backup use case is different from the what has been recently discussed in another thread. I'm trying to guard against hardware failure and other causes of destruction. I have a btrfs raid1 filesystem spread over two disks. I want to backup this filesystem regularly and efficiently to an external disk (same model as the ones in the raid) in such a way that * when one disk in the raid fails, I can substitute the backup and rebalancing from the surviving disk to the substitute only applies the missing changes. * when the entire raid fails, I can re-build a new one from the backup. The filesystem is mounted at its root and has several nested subvolumes and snapshots (in a .snapshots subdir on each subvol). Is it possible to do what I'm looking for? Michael -- Michael Schuerig mailto:michael@schuerig.de http://www.schuerig.de/michael/