Comment 11 for bug 1928690

From https://docs.openstack.org/kolla-ansible/ussuri/reference/storage/external-ceph-guide.html:

  ceph_nova_keyring (by default it’s the same as ceph_cinder_keyring)

In Ussuri we switched nova to use the same named keyring as Cinder by default, which is ceph.client.cinder.keyring. Perhaps that keyring does not have the necessary permissions to access the nova pool, or perhaps you have configuration overrides for nova.conf to use the old keyring name?

I would suggest removing any unnecessary configuration overrides, and either setting ceph_nova_keyring to the old value of ceph.client.nova.keyring, or updating the permissions of the cinder keyring to allow access to the nova pool.