From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sylvain Bauza <sylvain.bauza@digimind.com>
Subject: Win2003 disk corruption with kvm-1.0. and virtio
Date: Tue, 12 Feb 2013 15:30:37 +0100
Message-ID: <511A520D.4@digimind.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
To: kvm@vger.kernel.org
Return-path: <kvm-owner@vger.kernel.org>
Received: from mail-wi0-f182.google.com ([209.85.212.182]:36700 "EHLO
	mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1759634Ab3BLOav (ORCPT <rfc822;kvm@vger.kernel.org>);
	Tue, 12 Feb 2013 09:30:51 -0500
Received: by mail-wi0-f182.google.com with SMTP id hi18so173412wib.15
        for <kvm@vger.kernel.org>; Tue, 12 Feb 2013 06:30:50 -0800 (PST)
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

Hi,

We currently run Openstack Essex hosts with KVM-1.0 (Ubuntu 12.04) 
instances with qcow2,virtio,cache=none

For Linux VMs, no trouble at all but we do observe filesystem corruption 
and inconsistency (missing DLLs, CHKDSK asked by EventViewer, failure at 
reboot) with some of our Windows 2003 SP2 64b images.

At first boot, stress tests (CrystalDiskMark 3.0.2 and intensive CHKDSK) 
don't show up problems. It is only appearing 6 or 12h later.

Do you have any idea on how to prevent it ? Is cache=writethrough an 
acceptable solution ? We don't want to leave qcow2 image format as it 
does allow to do live snapshots et al.

Thanks for your inputs,
-Sylvain Bauza