.. ditaa:: 
           /------------------\         /----------------\
           |    admin-node    |         |      node1     |
           |                  +-------->+ cCCC           |
           |    ceph–deploy   |         |    mon.node1   |
           \---------+--------/         \----------------/
                     |
                     |                  /----------------\
                     |                  |      node2     |
                     +----------------->+ cCCC           |
                     |                  |     osd.0      |
                     |                  \----------------/
                     |
                     |                  /----------------\
                     |                  |      node3     |
                     +----------------->| cCCC           |
                                        |     osd.1      |
                                        \----------------/