Storage system and a file layer management method

A file layer management method for a storage system comprising:

• a storage apparatus for storing a file in a storage area managed by two or more layers;
• a file server communicable with said storage apparatus via a network;
• and a contents server for managing contents of said file, said contents server being communicable with said file server via a network, said file server managing said layer at which said file is stored, in accordance with an access state by said contents server, the file layer management method comprising:
• a file registration step, responsive to reception of a registration request for said file from said contents server, of registering said file in said storage apparatus and storing a file name of said file, a tag name as information representative of the contents of said file and relevant to said file, and access information to said file in a memory as file management information;
• a file read step, responsive to reception of a read request for said file from said contents server, for reading said file and updating said access information to said file;
• a file evaluation value calculation step of calculating at a predetermined timing an evaluation value of each of said tag name contained in said file management information by referring to said access information, storing said evaluation value in said memory as tag evaluation information, calculating an evaluation value of said file for each file name in said file management information by referring to said tag evaluation value information, and registering said evaluation value in said file management information;
• and
• a relocation control step of determining a storage destination layer of said file in accordance with said evaluation value of said file, and performing relocation of said file if said determined storage destination layer of said file is a storage destination layer different from a present storage destination layer.