From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com ([209.85.212.169]:61955 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750975AbaKFPCZ convert rfc822-to-8bit (ORCPT ); Thu, 6 Nov 2014 10:02:25 -0500 Received: by mail-wi0-f169.google.com with SMTP id n3so1705126wiv.0 for ; Thu, 06 Nov 2014 07:02:24 -0800 (PST) Received: from [192.168.2.15] ([212.103.222.226]) by mx.google.com with ESMTPSA id hk9sm8096111wjb.46.2014.11.06.07.02.22 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Nov 2014 07:02:23 -0800 (PST) Message-ID: <545B8D7E.6060606@gmail.com> Date: Thu, 06 Nov 2014 16:02:22 +0100 From: Francesco Morosinotto MIME-Version: 1.0 To: linux-btrfs@vger.kernel.org Subject: are btrfs snapshot helpful for backing up kvm qcow2 vm? Content-Type: text/plain; charset=US-ASCII Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi guys, I need to improve the backup strategy of my vms; At the moment I backup the machines once a week by stopping them, making a snapshot, exporting the xml descriptor file and backing up these files. I would prefer a daily online backup solution that allows me to take a snapshot with a minimum downtime. That's why I was planning to switch from etx4 to btrfs; my project will be to pause the vm, dump the memory and the xml descriptor file, make a snapshot of the subvolume storing the qcow2 file and after that resuming the machine. does this project makes any sense? What about performance? Am I going to experience bad performance having qcow2 over btrfs? I read on some old (two years) posts that btrfs was having bad fragmentation when dealing with qcow2 files, is this still happening? Thank you Francesco