Patent ID: 8281089
Filing Date: 2012-10-02
Classification: G06F

Abstract:
1. A storage system, comprising: a primary disk subsystem installed at a primary site; and a secondary disk subsystem installed at a secondary site and connected to the primary disk subsystem via a communication medium; wherein the primary disk subsystem includes a primary volume created from a plurality of disk devices, and a primary controller for controlling the primary volume and sending and receiving data to and from the secondary disk subsystem via the communication medium; wherein the secondary disk subsystem includes a secondary volume created from a plurality of disk devices, a secondary controller for controlling the volume and sending and receiving data to and from the primary disk subsystem via the communication medium, and differential information indicating a status of each of plurality of areas of the secondary volume; wherein the primary controller issues a pair creation command to the secondary controller with mode information indicating a copy mode of a remote copy between the primary volume and the secondary volume, wherein if the copy mode is a non-minimum copy mode according to the mode information, the storage system executes an initial copy process in which the primary controller, sends all data stored in the primary volume to the second disk subsystem via the communication medium and the second controller stores the received data in the second volume, and the storage system manages the primary volume and the secondary volume as a remote copy pair and executes control so that updated data in the primary volume is copied to the secondary volume via the communication medium, wherein if the copy mode is a minimum copy mode according to the mode information: