ceph config get -vs- ceph config-key get ??

I'm looking for clarification on which command should be used to manage configuration settings in Nautilus. It's not clear which of the "config" commands are supposed to be used. The documentation refers to "ceph config set/get ...", but the man page for ceph(8) only references "ceph config-key ...". What is the difference between "ceph config set" and "ceph config-key set" and which one is supposed to be used in Nautilus (and later) ? For example, setting values for the dashboard appears to work using "ceph config set mgr ...": ceph config set mgr mgr/dashboard/mon02/server_addr 10.4.3.22 But trying to read this value back using "config get" fails: ceph config get mgr mgr/dashboard/mon02/server_addr Error EINVAL: unrecognized entity 'mgr' Furthermore, "ceph config ls" shows a rather long list of keys that should be able to be read back, but attempting to fetch them with "ceph config get" always results in the same above error "EINVAL: unrecognized entity 'mgr'". Is this a known bug? The inconsistencies and documentation are confusing. thanks, Wyllys Ingersoll