From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.jrs-s.net ([173.230.137.22]:59495 "EHLO mail.jrs-s.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752986AbbITBbm (ORCPT ); Sat, 19 Sep 2015 21:31:42 -0400 Subject: Re: BTRFS as image store for KVM? To: Gert Menke , linux-btrfs@vger.kernel.org References: <55F88ECC.1040604@menke.ac> From: Jim Salter Message-ID: <55FE0B42.50300@jrs-s.net> Date: Sat, 19 Sep 2015 21:26:26 -0400 MIME-Version: 1.0 In-Reply-To: <55F88ECC.1040604@menke.ac> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: I can't recommend btrfs+KVM, and I speak from experience. Performance will be fantastic... except when it's completely abysmal. When I tried it, I also ended up with a completely borked (btrfs-raid1) filesystem that would only mount read-only and read at hideously reduced speeds after about a year of usage in a small office environment. Did *not* make me happy. ZFS, by contrast, works like absolute gangbusters for KVM image storage. Just create a dataset, drop a .qcow2 file in it, and off to the races. I don't recommend messing about with zvols, it's a PITA and isn't necessary. HTH. On 09/15/2015 05:34 PM, Gert Menke wrote: > Hi everybody, > > first off, I'm not 100% sure if this is the right place to ask, so if > it's not, I apologize and I'd appreciate a pointer in the right > direction. > > I want to build a virtualization server to replace my current home > server. I'm thinking about a Debian system with libvirt/KVM. The > system will have one or two SSDs and five harddisks with some kind of > software RAID5 for storage. I'd like to have a filesystem with data > checksums, so BTRFS seems like the right way to go. However, I read > that BTRFS does not perform well as storage for KVM disk images. > (See here: http://www.linux-kvm.org/page/Tuning_KVM ) > > Is this still true? > > I would appreciate any comments and/or tips you might have on this topic. > > Is anyone using BTRFS as an image store? Are there any special > settings I should be aware of to make it work well? > > Thanks, > Gert > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html