In this section we'll cover strategies for growing capacity to meet your users' never-ending thirst for storage. In Chapter 5, Deploying a Virtual Sandbox Cluster we used ceph-ansible through Vagrant to add additional components to our cluster; in production on bare metal one can also use ceph-ansible directly to manage many aspects of cluster expansions. The addition of entire OSD hosts and logical racks to a running cluster is straightforward but must be planned carefully. Chapter 8, Ceph Architecture: Under the Hood of Learning Ceph, walks us through editing the CRUSH map to add logical racks and OSD nodes.
Below we'll summarize the process for adding a new OSD host to an existing Ceph cluster in a more manual, hands-on fashion. ...
