Data storage systems, data storage method

PROBLEM TO BE SOLVED: To enhance reliability of a data storage system. SOLUTION: Information (update data) about an operation condition of a production device 40 is transmitted from an on-line controller 30 to a storage server 10A. The storage server 10A updates a database provided in the storage server 10A, based on the update data. The storage server 10A transfers the update data to storage servers 10B, 10C. The storage servers 10B, 10C update databases provided in the storage servers 10B, 10C, based on the transferred update data. COPYRIGHT: (C)2010,JPO&INPIT