Am 12.10.2012 10:53, schrieb Tiziano Müller: > Am Freitag, den 12.10.2012, 10:33 +0200 schrieb Stefan Hajnoczi: >> On Thu, Oct 11, 2012 at 03:33:23PM +0200, Tiziano Müller wrote: >>> Checking the image using `qemu-img check` then gives something like >>> this: >>> >>> ERROR OFLAG_COPIED: offset=3bc30000 refcount=1 >>> ERROR offset=c7e331: Cluster is not properly aligned; L2 entry >>> corrupted. >> >> Is any other program accessing the qcow2 image on the host while the VM >> is running? > >> For example, are you running qemu-img on the image while the VM is >> running? > > On some VMs we tried to extract filesystem snapshots at runtime: > > qemu-img convert -s snapshot-id original.qcow2 snapshot.qcow2 > > (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". > > 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
