The most important thing to capture is the health status of Ceph. The main reporting item is the overall health status of the cluster, either HEALTH_OK, HEALTH_WARN, or HEALTH_ERR. By monitoring this state, you will be alerted any time Ceph itself thinks that something is not right. In addition to this, you may also want to capture the status of the PGs and number of degraded objects, as they can provide additional information as to what might be wrong without having to actually log on to a Ceph server and use the Ceph toolset to check the status.