1. A computer system, comprising: a server on which an application providing a service runs; and a storage system for storing data to be used by the application, the server including a first processor, a first memory, a cache device in which a server cache for temporarily storing data is set up, and a first interface for coupling to another apparatus, the storage system including a controller and a plurality of storage devices, the controller including a second processor, a second memory, and a second interface for coupling to another apparatus, the server including an operating system for controlling the server, the storage system including a storage cache for temporarily storing data and a storage control part for controlling the storage system, the operating system including a cache driver for controlling the server cache, wherein the operating system is configured to hold access information storing a frequency of reading data and a frequency of writing data, and wherein the cache driver is configured to: update the access information in a case where an I/O request is received from the application; analyze access characteristics of data that is a target for the I/O request based on the updated access information; and determine whether to store the data that is the target for the I/O request in the server cache based on a result of analysis of the access characteristics.