STORAGE SYSTEM AND STORAGE CONTROL METHOD FOR USING STORAGE AREA BASED ON SECONDARY STORAGE AS CACHE AREA

摘要

In general, a DRAM is used as a cache memory, and when attempting to expand the capacity of the cache memory to increase the hit ratio, the DRAM is required to be physically augmented, which is not a simple task. Consequently, a storage system uses a page, which conforms to a capacity virtualization function (for example, a page allocatable to a logical volume in accordance with Thin Provisioning), as a cache area. This makes it possible to dynamically increase and decrease the cache capacity.