From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f174.google.com ([209.85.223.174]:33399 "EHLO mail-io0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751289AbdILLCe (ORCPT ); Tue, 12 Sep 2017 07:02:34 -0400 Received: by mail-io0-f174.google.com with SMTP id k101so2359175iod.0 for ; Tue, 12 Sep 2017 04:02:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <2a0186c7-7c56-2132-fa0d-da2129cde22c@rqc.ru> References: <2ee9f15b-a11a-886e-2460-557bb9f8d41d@rqc.ru> <69e843f4-1233-261a-3b88-306359ef20c9@rqc.ru> <20170912103214.6dzjlugcr7q47x6g@angband.pl> <2a0186c7-7c56-2132-fa0d-da2129cde22c@rqc.ru> From: Timofey Titovets Date: Tue, 12 Sep 2017 14:01:53 +0300 Message-ID: Subject: Re: qemu-kvm VM died during partial raid1 problems of btrfs To: Marat Khalili Cc: Adam Borowski , Duncan <1i5t5.duncan@cox.net>, linux-btrfs Content-Type: text/plain; charset="UTF-8" Sender: linux-btrfs-owner@vger.kernel.org List-ID: 2017-09-12 13:39 GMT+03:00 Marat Khalili : > On 12/09/17 13:01, Duncan wrote: >> >> AFAIK that's wrong -- the only time the app should see the error on btrfs >> raid1 is if the second copy is also bad > > So thought I, but... > >> IIRC from what I've read on-list, qcow2 isn't the best alternative for >> hosting VMs on >> top of btrfs. > > Yeah, I've seen discussions about it here too, but in my case VMs write very > little (mostly logs and distro updates), so I decided it can live as it is > for a while. But I'm looking for better solutions as long as they are not > too complicated. > > > On 12/09/17 13:32, Adam Borowski wrote: >> >> Just use raw -- btrfs already has every feature that qcow2 has, and does >> it >> better. This doesn't mean btrfs is the best choice for hosting VM files, >> just that raw-over-btrfs is strictly better than qcow2-over-btrfs. > > Thanks for advice, I wasn't sure I won't lose features, and was too lazy to > investigate/ask. Now it looks simple. > > -- > > With Best Regards, > Marat Khalili > -- > 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 The main problem with Raw over Btrfs is that (IIRC) no one support btrfs features. - Patches for libvirt not merged and obsolete - Patches for Proxmox also not merged - Other VM hypervisor like Virtualbox, VMware just ignore btrfs features. So with raw you will have a problems like: no snapshot support But yes, raw over btrfs the best performance wise solution. -- Have a nice day, Timofey.