Hi, We are running a ceph cluster that is currently on Luminous. At this point most of our clients are also Luminous, but as we provision new client hosts we are using client versions that are more recent (e.g Octopus, Pacific and more recently Quincy). Is this safe? Is there a known list of what client versions are compatible with what server version? We are only using RBD and are specifying rbd_default_features (the same) on all server and client hosts. regards Mark