roles:
- [mon.a, mon.c, mgr.y, mds.a, osd.0, osd.1, osd.2, osd.3]
- [mon.b, mgr.x, mds.b, mds.c, osd.4, osd.5, osd.6, osd.7]
- [client.0, client.1]
openstack:
- volumes: # attached to each instance
count: 4
size: 30 # GB