roles:
-- [osd.0, osd.1, osd.2, client.0, mon.a, mgr.x]
-- [osd.3, osd.4, osd.5, client.1, mon.b, mgr.y]
-- [osd.6, osd.7, osd.8, client.2, mon.c, mgr.z]
-- [osd.9, osd.10, osd.11, client.3, mon.d]
-- [osd.12, osd.13, osd.14, client.4, mon.e]
+- [host.a, client.0]
+- [host.b, client.1]
+- [host.c, client.2]
+- [host.d, client.3]
+- [host.e, client.4]