The Sun StorEdge 3900 series are factory-installed in the Expansion Rack, which is the same enclosure used for several other Sun storage products, providing customers a consistent look and feel. The customer-accessible areas of each storage system are clearly labeled as such.The Sun StorEdge 3960 system uses partner pairs of Sun StorEdge T3 arrays. A maximum of eighteen Sun StorEdge T3 arrays (or nine partner pairs) can reside in the Sun StorEdge 3960 system with expansion cabinet. Both the master and slave arrays of a partner pair are connected to one of the two Fibre Channel switches (within a cabinet) for high availability purposes. They are also connected via an Ethernet connection to the Ethernet hub for administrative purposes.