From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TNia2-0007oo-VX for qemu-devel@nongnu.org; Mon, 15 Oct 2012 07:11:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TNiZx-0007zU-67 for qemu-devel@nongnu.org; Mon, 15 Oct 2012 07:11:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9072) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TNiZw-0007zN-UI for qemu-devel@nongnu.org; Mon, 15 Oct 2012 07:11:25 -0400 Message-ID: <507BEF57.1010505@redhat.com> Date: Mon, 15 Oct 2012 13:11:19 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <1349962403.4696.51.camel@storm> <20121012083315.GB14822@stefanha-thinkpad.redhat.com> <1350032009.4696.84.camel@storm> In-Reply-To: <1350032009.4696.84.camel@storm> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] Silent filesystem/qcow2 corruptions with qemu-kvm-1.0 and 1.1.1 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: tiziano.mueller@stepping-stone.ch Cc: Stefan Hajnoczi , qemu-devel Am 12.10.2012 10:53, schrieb Tiziano M=C3=BCller: > Am Freitag, den 12.10.2012, 10:33 +0200 schrieb Stefan Hajnoczi: >> On Thu, Oct 11, 2012 at 03:33:23PM +0200, Tiziano M=C3=BCller wrote: >>> Checking the image using `qemu-img check` then gives something like >>> this: >>> >>> ERROR OFLAG_COPIED: offset=3D3bc30000 refcount=3D1 >>> ERROR offset=3Dc7e331: Cluster is not properly aligned; L2 entry >>> corrupted. >> >> Is any other program accessing the qcow2 image on the host while the V= M >> is running? >=20 >> For example, are you running qemu-img on the image while the VM is >> running? >=20 > On some VMs we tried to extract filesystem snapshots at runtime: >=20 > qemu-img convert -s snapshot-id original.qcow2 snapshot.qcow2 >=20 > (yes, that's not consistent, we're switching to external snapshots). > But that should open the image read-only, right? Yes, in theory that should be harmless and even produce a correct copy of the snapshot. > Other operations where the qemu-monitor-commands "savevm" and "delvm".=20 >=20 > Although: we created a new qcow2 and even in that the filesystem got > corrupted without any of the above actions. So we're pretty confident > that those operations are not the sole cause. So no internal snapshots are involved at all with this new image? I'm asking because in the past non-reproducible failures were reported with snapshots, but I'm not aware of any case that didn't use snapshots. Any other non-default feature that you used, like compression? Kevin