Intro to Ceph

• Managers: A daemon (ceph-mgr) is responsible for keeping track of runtime metrics and the current state of the Ceph cluster, including storage utilization, current performance metrics, and system load. The Ceph Manager daemons also host python-based modules to manage and expose Ceph cluster information, including a web-based Ceph Dashboard and . At least two managers are normally required for high availability.

• MDSs: A Ceph Metadata Server (MDS, ceph-mds) stores metadata on behalf of the (i.e., Ceph Block Devices and Ceph Object Storage do not use MDS). Ceph Metadata Servers allow POSIX file system users to execute basic commands (like , find, etc.) without placing an enormous burden on the Ceph Storage Cluster.