Abstract: Embodiments include methods, apparatus, and systems for reserving memory space for Peripheral Component Interconnect (PCI) devices. One embodiment includes a method that determines peripheral devices that are connected to a host computer through a PCI switch or PCI bridge and then presents virtual devices as being connected to the PCI switch or PCI bridge. Bus numbers and memory are reserved for the virtual devices and assigned to PCI devices that are hot plugged to the host computer.

Abstract: A bridge comprises an interface to a plurality of hosts, an interface to a single-ported storage drive and arbitration logic. The arbitration logic controls and permits concurrent access by the hosts to the single-ported storage drive so that the bridge need not store read or write data being received from or provided to the storage drive.

Abstract: A system includes a peripheral device and an expander having interfaces to couple to one or more peripheral devices and an expander. The expander has a storage to store entries containing routing information used to route a request received by the expander to one of the interfaces, wherein each interface is allocated to a respective set of routing information entries. Mapping logic remaps unused routing information of one of the interfaces to one or more other interfaces to expand capacity of the one or more other interfaces.