Comment 5 for bug 1755756

I hit this because I had a backlevel qemu-utils compared to what devstack installs in our gate jobs. Devstack installs cloud-archive:pike when deploying queens and installs qemu-utils from there. If you're on xenial and getting qemu-utils from the base distro, this may be your problem.

Note that the problem is that nova calls qemu-img info with --force-shared, which isn't in older versions, and thus it explodes without even looking at the image.