Storage subsystem, information processing system and method of controlling I/O interface

摘要

A storage subsystem includes a disk control unit having a cache memory and disk units under control thereof is connected to a central processing unit through an interface such as FC-SB2 which the central processing unit issues an I/O request including a chain of plural commands and data asynchronously with responses from the disk control unit. The disk control unit executes commands having target data hit on the cache memory independently of the order of receipt of plural commands from the central processing unit, in parallel with the staging of target data of commands resulting in cache misses from a disk unit to the cache memory.