Provided is a computer system including: one first server; a plurality of second servers; and a plurality of storage subsystems, in which the computer system applies to each file stored in the storage subsystems one of a first file storage mode and a second file storage mode in a distributive manner, the first server integrates directory structures that are unique throughout the respective second servers to provide the integrated directory structures as a directory structure that is unique throughout the computer system to the client computer, and at least one of the first server and the second servers analyzes a utilization state of the file and switches a file storage mode that is currently applied to the file to the other file storage mode based on a change in the analyzed file utilization state.