Comment 2 for bug 1939719

This part of the code is a bit tricky:
https://github.com/openstack/nova/blob/stable/ussuri/nova/virt/libvirt/driver.py#L9616-L9628

The file copy is from the live-migration source host to the destination host and the command is run on the *destination* host instead of the source host. My gut feeling is that live_migration_inbound_addr is only applicable when running live-migration related operations on the *source* host after the destination host passes live_migration_inbound_addr of the destination host itself as the *inbound* address using the pre_live_migration phase.

Using instance.host instead of using an explicit address probably doesn't reflect the operator's intention of setting live_migration_inbound_addr so it's an upstream issue ultimately IMHO. However, using config_drive_format=iso9660 is known tricky in the upstream as the code comment suggests:
https://bugs.launchpad.net/nova/+bug/1246201

So the quickest workaround would be using config_drive_format=vfat to avoid running that part of the code.

$ juju config nova-compute-* config-flags='config_drive_format=vfat'