File server, file management system and file management method

摘要

When receiving a file access from the client, the file access program refers to the mapping table, and processes an access to files of on volumes of RAID groups. The file server analyzes the file access states, and groups the files depending on the access time period, defines the file migration pattern based on the grouping, migrates the files, and then carries out a power management operation like a spin-down/-up operation on the RAID groups based on the migration pattern.