Chapter 1. Overview

The Red Hat Ceph Storage cluster is the foundation for all Ceph deployments. Based upon Reliable Autonomic Distributed Object Store (RADOS), Ceph Storage Clusters consist of two types of daemons:

  • A Ceph Object Storage Device (OSD) stores data as objects within placement groups assigned to the OSD
  • A Ceph Monitor maintains a master copy of the cluster map

A Red Hat Ceph Storage cluster can contain thousands of storage nodes. A minimal system will have at least one Ceph Monitor and three Ceph OSDs for peering and object durability. A production system will have three or more Monitors for high availability and typically a minimum of 50 OSDs for acceptable load balancing, re-balancing and recovery. See the Red Hat Ceph Storage Installation Guide for Red Hat Enterprise Linux or Ubuntu for details.