The two FireWire ports on 2nd generation Drobos (and Drobo S and DroboPro, as well) allow multiple Drobo devices to connect to one computer (rather than multiple computers to connect to one Drobo). The two FireWire ports support a daisy-chained configuration. You can find out more about daisy chaining Drobos in: How can I attach multiple Drobos storage devices to my computer? Although we don't li