A storage subsystem and a storage controller adapted to take advantage of
high data transfer rates of fibre channels while offering enhanced
reliability and availability and capable of connecting with a plurality of
host computers having multiple different interfaces. A loop is provided to
serve as a common loop channel having fibre channel interfaces. Host
interface controllers (HIFC) connected to host computers having different
interfaces permit conversion between the fibre channel interface and a
different interface as needed. Control processors, shared by the host
interface controllers, each reference FCAL (fibre channel arbitrated loop)
management information to capture a frame having an address of the
processor in question from among the frames passing through the loop. I/O
processing is then carried out by the controller in accordance with a
range of logical unit numbers (LUN) set in the captured frame.
