Computer system, cache management method, and computer

A computer system comprising: a server on which an application operates; and a storage system that stores data used by the application, the server including an operating system for controlling the server, the operating system including a cache driver for controlling a cache, the cache driver storing access management information for managing the number of accesses to a partial storage area of a volume provided by the storage system, and the cache driver being configured to: manage the number of accesses to the partial storage area of the volume by using the first access management information; replace the storage area to which the number of accesses is to be managed based on a predetermined replacement algorithm; and control arrangement of data in the server cache based on the first access management information.