Hi, we have faced some problems when creating volumes to add to VMs,  to see what was happening I activated the Debug=True mode of Cinder in the cinder.conf file. 
I see that when I try to create a new volume I get the following in the log:

"DEBUG cinder.volume.drivers.rbd connecting to (conf=/etc/ceph/ceph.conf, timeout=-1) _do_conn /usr/lib/python3.6/site-packages/cinder/volume/drivers/rbd.py:431”

I’m using OpenStack Train and Ceph Octopus.
When I check with openstack volume service list

+------------------+----------------------+------+---------+-------+----------------------------+
| Binary           | Host                 | Zone | Status  | State | Updated At                 |
+------------------+----------------------+------+---------+-------+----------------------------+
| cinder-scheduler | spsrc-controller-1      | nova | enabled | up    | 2021-05-11T10:06:39.000000 |
| cinder-scheduler | spsrc-controller-2      | nova | enabled | up    | 2021-05-11T10:06:47.000000 |
| cinder-scheduler | spsrc-controller-3      | nova | enabled | up    | 2021-05-11T10:06:39.000000 |
| cinder-volume    | rbd:volumes@ceph-rbd | nova | enabled | down  | 2021-04-11T10:48:42.000000 |
| cinder-backup    | spsrc-mon-2                      | nova | enabled | up    | 2021-05-11T10:06:47.000000 |
| cinder-backup    | spsrc-mon-1                      | nova | enabled | up    | 2021-05-11T10:06:44.000000 |
| cinder-backup    | spsrc-mon-3                      | nova | enabled | up    | 2021-05-11T10:06:47.000000 |
+------------------+----------------------+------+---------+-------+——————————————+

So cinder-volume is Down,

I compare "cinder-backup" Ceph config with "cinder-volume", and they are equal! so why only one of them works?
diff /etc/kolla/cinder-backup/ceph.conf /etc/kolla/cinder-volume/ceph.conf

I go inside the "cinder_volume" container
docker exec -it cinder_volume /bin/bash

Try listing cinder volumes, works!
rbd -p cinder.volumes --id cinder -k /etc/ceph/ceph.client.cinder.keyring ls

Any Ideas. Kind regards.