FWIW: While trying to restore (apply) a snapshot on a Windows VM (ie: qemu-img snapshot -a snapshotname windows.qcow2 where the image file is 150gb in size,) I got the above error:
qemu-img: /build/buildd/qemu-2.0.0+dfsg/block/qcow2-refcount.c:467: update_refcount_discard: Assertion `d->bytes + length == new_end - new_start' failed. (My VM is now broken.) This is the only reference that I found using Google. HTH -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1349972 Title: qcow2-refcount: qemu-io crashes on 'discard' command Status in QEMU: New Bug description: qemu-io is killed by SIGIOT at the 'discard' command on the image having no refcount information. Sequence: 1. Unpack test.img and backing_img.qed in the same directory (see the attached archives for images) 2. Make a copy of test.img to copy.img (qemu-io modifies the image before being kill, therefore the image backup is necessary) 3. Run the command qemu-io copy.img -c 'discard 2210816 2856448' Result: qemu-io is killed by SIGIOT with the reason: qemu-io: block/qcow2-refcount.c:468: update_refcount_discard: Assertion `d->bytes + length == new_end - new_start' failed. The image was generated by the image fuzzer. qemu.git HEAD: 1d80eb7a680d To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1349972/+subscriptions
