However, I could not read the logs the way Dmitriy suggested, it simply returns

-- Logs begin at Mon 2020-10-05 14:30:22 UTC, end at Mon 2020-10-12 11:17:20 UTC. -- -- No entries --

so I couldn't investigate the request. ( I tried this on both utility and cinder api containers on the management node and on the storage and respective compute node to be sure)

... it seems that I've missed the storage node, since I just tried again and got something:

Oct 12 12:57:09 bc1bl10 cinder-volume[30198]: 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server [req-e9175ddf-8ee4-4135-b89b-6e9c61f63999 2223bca5520044b7b7646e2f8141a440 5fbba868d04b47fa87a72b9dd821ee12 - default default] Exception during message handling: cinder.exception.InvalidInput: Invalid input received: Connector doesn't have required information: initiator 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server Traceback (most recent call last): 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/cinder/volume/manager.py", line 4471, in _connection_create 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server self.driver.validate_connector(connector) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/cinder/volume/drivers/lvm.py", line 859, in validate_connector 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server return self.target_driver.validate_connector(connector) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/cinder/volume/targets/iscsi.py", line 297, in validate_connector 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server raise exception.InvalidConnectorException(missing='initiator') 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server cinder.exception.InvalidConnectorException: Connector doesn't have required information: initiator 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server During handling of the above exception, another exception occurred: 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server Traceback (most recent call last): 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/oslo_messaging/rpc/server.py", line 165, in _process_incoming 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/oslo_messaging/rpc/dispatcher.py", line 276, in dispatch 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/oslo_messaging/rpc/dispatcher.py", line 196, in _do_dispatch 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/cinder/volume/manager.py", line 4554, in attachment_update 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server connector) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server File "/openstack/venvs/cinder-21.0.1/lib/python3.6/site-packages/cinder/volume/manager.py", line 4473, in _connection_create 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server raise exception.InvalidInput(reason=six.text_type(err)) 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server cinder.exception.InvalidInput: Invalid input received: Connector doesn't have required information: initiator 2020-10-12 12:57:09.554 30198 ERROR oslo_messaging.rpc.server

Kind regards, Oliver