I can confirm that installing a newer version of libvirt fixes the issue. We just did this for an nova-libvirt container in the Openstack Victoria release, wich we had upgraded from Rocky.
We used the latest available libvirt version for Ubuntu 20.04: 6.0.0-0ubuntu8.12 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1906266 Title: After upgrade: "libvirt.libvirtError: Requested operation is not valid: format of backing image %s of image %s was not specified" To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-archive/+bug/1906266/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
