Patent ID: 6850998

Claim:
A method for controlling a disk array system including a plurality of disk drives and a disk array control device for controlling the plurality of disk drives, the disk array control device comprising: a first interface unit for exchanging information with a host system; a second interface unit for exchanging information with the plurality of disk drives; a plurality of memory units shared by the first and second interface units; and switching means connected to the first and second interface units through a plurality of first paths and each of the plurality of memory units through a plurality of second paths, for controlling exchange of information in packets between the plurality of memory units, first interface unit, and second interface unit; wherein said switching means temporarily holds information to be transferred, and information in packet form, if said information has been stored in a selected one of said memory units, from said one memory unit to said host system through said first interface and transfers information in packet form, if said information has been stored in a selected one of said disk drives, from said one disk drive to said host system through said first interface in response to a data reading instruction or transfers information in packet form from from said host system to a selected one of said memory units and transfers information in packet form from said one memory unit to a selected one of said disk drive through said second interface in response to a data writing instruction; the method for controlling the disk array system comprising the steps of: receiving the packets from at least one of the host system or the disk drives through the first or second interface units, by the switching means; and temporarily holding a number of the received packets greater than a number of the first paths, by the switching means.