Patent ID: 7069403

Claim:
A storage system, comprising: a plurality of storage units configured to store data; a first control unit configured to control data written by a second control unit, the first control unit including: a channel adaptor configured to receive data written by the second control unit; a disk adaptor configured to transfer data to the plurality of storage units and receive data from the plurality of storage units; and a memory configured to store data and/or information received from the channel adaptor and the disk adaptor; and a communication cable that connects the first control unit and a third control unit, wherein the first control unit is configured to communicate management information with the third control unit via the communication cable, and wherein based on the management information the first control unit and the third control unit are configured to determine common management information that describes a relationship between a plurality of data stored in the first control unit and in the third control unit, and to store data, which is selected based on the common management information, and which is from said memory, in the plurality of storage units.