What I think is happening is that you are creating a qcow2 with the '-b' option rather than using libvirt's 'snapshot' functionality. As such, the backing store is unknown to libvirt so it doesn't know to add the file. libvirt is able to probe the file, but this could be a security risk and needs to be enabled by the administrator. That option is:
allow_disk_format_probing = 1 in /etc/libvirt/qemu.conf. Please see the following for more details: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/470636/comments/18 https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/656173/comments/6 Please either use libvirt's 'snapshot' functionality or set 'allow_disk_format_probing = 1' and report back. ** Changed in: libvirt (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1658198 Title: multi-level stacked qcow2 files are not properly handled in Apparmor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1658198/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
