Comment 47 for bug 1806156

Also ran into this issue when upgrading Rocky to Stein using kolla-ansible, all cinder-volume containers were up and running.
I then checked the database via

openstack volume service list

and found some cinder-volume entries with state 'down' for no longer existing hostnames.
After removing all entries with state 'down' via

cinder-manage service remove cinder-volume $old_hostname

from inside the cinder-api container, the task completed sucessfully.