Patent ID: 6813684
Filing Date: 2004-11-02
Classification: G06F

Abstract:
A disk system, comprising:a CPU for issuing an I/O command; a disk drive; a disk cache memory for storing disk data in each of its segments selectively; and a disk controller for controlling said disk drive and said disk cache memory; wherein each segment of said cache memory includes a field for storing an area number; and wherein said disk controller includes means for recording a value corresponding to a type of said I/O command in said area number field when storing disk data in said cache memory according to said I/O command issued from said CPU, updating said area number to a value corresponding to a type of said I/O command each time it accesses data in said cache memory according to said issued I/O command, and controlling swapping out of data from each area of said cache memory according to a predetermined upper limit size set for said area partitioned by said area number in said cache memory.