CACHE SYSTEM FOR DISK ARRAY

摘要

PURPOSE: To reduce or eliminate redundant access to a disk necessary for generating parity data. CONSTITUTION: This cache system is provided with a cache memory 50 for holding data transferred between a host system 10 and a disk array 30. The disk array 30 is provided with a plurality of disk storage device 34, 36, 38 and 40 storing data in the state of slides. Each slide is provided with a multi- sector parity block related with a multi-sector unit and another array storage device in each of not less than two storage devices of the array and with a means linking data forming a slide for a cache as a cache data unit operated within the cache as a single object and a related parity. Consequently, when committing a cache unit at the bottom part of a list in a disk, a possibility that most of data forming the slides exists within a cash is increased so that the number of redundant access to the disk necessary for generating parity data is reduced or eliminated.