Storage system adapter and method of using same

Computer-readable memory comprising executable computer program instructions that when executed cause:

• configuring of at least one network node in a network comprising a plurality of network nodes, the network nodes being comprised in an adapter that may be used in a data storage system to permit data communication among data exchanging devices and data storage system processors residing in the data storage system, the devices being external to the adapter, the configuring of the at least one network node changing a topology of the network from at least one network topology to at least one other network topology, the communication permitted by the network among at least certain of the processors and the devices being different depending upon which of the one topology and the other topology the network has.

Method of using an adapter in a data storage system to permit data communication among data exchanging devices and data storage system processors, the processors residing in the data storage system, the devices being external to the adapter, the method comprising the steps of:

• configuring at least one network node in a network comprising a plurality of network nodes in the adapter, the configuring of the at least one network node changing a topology of the network from at least one network topology to at least one other network topology, the communication permitted by the network among at least certain of the processors and the devices being different depending upon which of the one topology and the other topology the network has.

Method according to claim 26, further comprising providing in the adapter at least one optical transceiver that may be used in coupling the at least one host computer node to the network.