Page Comparison

...

• clients: Set of hosts that must be ceph-client. These hosts will access to the storage cluster

• mons: Set of hosts to that must be ceph-mon. These hosts will maintain a map of the state of the cluster
  

• osds: Set of hosts to that must be ceph-osd

...

• . These hosts will interact with the logical disk to stock the data

More details in the documentation here.

The inventory must define these variables to run the step:

• ceph_cluster_network: Address block to access to cluster network
• ceph_public_network: Address block to access to public network (ie Internet)

• ceph_osd_disk: Device to stock datas (only for ceph-osd hosts)

• osd_pool_default_min_size: Minimal number of available OSD to ensure cluster success (best: ceil(osd_pool_default_size / 2.0))

• osd_pool_default_size: Number of OSD in the cluster

...