Image shows the layout of the servers and switches in Oracle Exadata Database Machine X3-2 Full Rack. From the bottom to the top of the rack, the layout is as follows:
U1: Sun Datacenter InfiniBand Switch 36
U2 - U15: Exadata Storage Servers
U16 - U19: Oracle Database servers
U20: Sun Datacenter InfiniBand Switch 36
U21: Cisco switch
U22: Sun Datacenter InfiniBand Switch 36
U23 - U26: Oracle Database servers
U26 - U40: Exadata Storage Servers
U41 - U42: Empty