Patent ID: 7441145
Filing Date: 2008-10-21
Classification: G06F

Abstract:
1. A computer system comprising: a first storage system connected to a first computer used in normal operation, a second storage system connected to the first storage system to store a copy of data stored in the first storage system, a third storage system connected to the second storage system to store a copy of data stored in the second storage system, a fourth storage system connected to the first computer used in normal operation, a fifth storage system connected to the fourth storage system to store a copy of data stored in the fourth storage system, a sixth storage system connected to the fifth storage system to store a copy of data stored in the fifth storage system, a second computer connected to the third storage system and the sixth storage system, a first transmission path extending from the first computer to the second computer through the first storage system, the second storage system, and the third storage system, a second transmission path extending from the first computer to the second computer through the fourth storage system, the fifth storage system, and the sixth storage system, wherein each of the first computer and the second computer having a memory, a control unit controlling data input/output in the storage systems by executing the control program, and an input/output processing device, the memory storing a control program, the control unit, the input/output processing device controlling to exchange data and control signals between the storage systems, wherein the first computer sends control I/O on the first transmission path and the second transmission path, wherein each of the storage systems transfers received control I/O to one of its connected storage system or the second computer, and wherein the second computer: monitors control I/O transferred on the first transmission path and the second transmission path, requests state information of the storage systems on the transmission path that has failed to transfer the control I/O, and requests shutting down to the storage systems on the other transmission path which are associated with the storage systems in a failure location specified based on the obtained state information.