Red Hat Bugzilla – Bug 729572
qcow2: Loading internal snapshot can corrupt image
Last modified: 2013-01-09 19:13:02 EST
We don't support internal snapshots, but it's not compiled out, this is an image corruption bug and upstream has a fix. So let's fix it anyway. Reproducible with this script: qemu-img create -f qcow2 /tmp/sn.qcow2 64M qemu-img snapshot -c foo /tmp/sn.qcow2 qemu-io -c 'write -b 0 4M' /tmp/sn.qcow2 qemu-img snapshot -a foo /tmp/sn.qcow2 qemu-img check /tmp/sn.qcow2
Reproduced this issue with qemu-kvm-0.12.1.2-2.180.el6 using comment0 steps. Results: #qemu-img check /tmp/sn.qcow2 ERROR cluster 1 refcount=0 reference=1 ERROR cluster 7 refcount=0 reference=1 ERROR cluster 8 refcount=0 reference=1 ERROR cluster 9 refcount=0 reference=1 ERROR cluster 10 refcount=0 reference=1 ERROR cluster 11 refcount=0 reference=1 ERROR cluster 12 refcount=0 reference=1 ERROR cluster 13 refcount=0 reference=1 ERROR cluster 14 refcount=0 reference=1 ERROR cluster 15 refcount=0 reference=1 ERROR cluster 16 refcount=0 reference=1 Verified this issue with qemu-kvm-0.12.1.2-2.184.el6 Results: #qemu-img check /tmp/sn.qcow2 No errors were found on the image. This issue has been fixed.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2011-1531.html