The preliminary storage subsystem which possesses preliminary volume the data management system

摘要

PPROBLEM TO BE SOLVED: To provide a data management system, data management method, and data management program which can be operated by using a small capacity of line and multiplies data among a plurality of storage sub-systems which can be operated by using a low capacitance of line by using a synchronous system data transfer system. PSOLUTION: In a main storage sub-system 2, a semi-synchronous order guarantee mode in which a write IO command (data write command) from a higher order device 1 is temporarily stored in a buffer 22 and write IO commands are transferred altogether and a non-synchronous mode in which differential information is managed in a data table 23 and differential data based on the data table 23 are transferred are used according to line situations. PCOPYRIGHT: (C)2008,JPO&INPIT