Managing monitors

As a storage administrator, you can deploy additional monitors using placement specification, add monitors using service specification, add monitors to a subnet configuration, and add monitors to specific hosts. Apart from this, you can remove the monitors.

By default, a typical IBM Storage Ceph has three or five monitor daemons deployed on different hosts.

IBM recommends deploying five monitors if there are five or more nodes in a cluster.

Ceph deploys monitor daemons automatically as the cluster grows, and scales back monitor daemons automatically as the cluster shrinks. The smooth execution of this automatic growing and shrinking depends upon proper subnet configuration.

If your monitor nodes or your entire cluster are located on a single subnet, then cephadm automatically adds up to five monitor daemons as you add new hosts to the cluster. cephadm automatically configures the monitor daemons on the new hosts. The new hosts reside on the same subnet as the bootstrapped host in the storage cluster.

cephadm can also deploy and scale monitors to correspond to changes in the size of the storage cluster.