Labeling hosts

The Ceph Orchestrator supports assigning both general labels and topological labels to hosts. Labels can be free-form with any text string. Topological labels are input with a hardware identifier and a user label. Each host can have multiple labels.

Labels

Labels are free-form user specified text. For example, use a label such as mycluster_mon on all hosts on which you want to deploy Ceph Monitor daemons. A second label of mycluster_mgr can then be placed on all hosts on which you want to deploy Ceph Manager daemons.

Labeling all the hosts in the storage cluster helps to simplify system management tasks by allowing you to quickly identify the daemons running on each host. In addition, you can use the Ceph Orchestrator or a YAML file to deploy or remove daemons on hosts that have specific host labels.

Topological labels

Use topological labels in multi-rack environments to help create distinct services for each rack. Topological labels enable upgrade operations on specific hosts.

For more information, see Running a staggered upgrade.

Before labeling hosts, be sure that you have a storage cluster installed and bootstrapped.