Patent ID: 9032144
Filing Date: 2015-05-12
Classification: G06F

Abstract:
1. A virtual tape device arranged in a main center comprising: a logical volume that stores data received from a host computer, the logical volume being coupled to a first library device arranged in the main center and the logical volume also being coupled, via a network, to a second library device, the second library device being arranged in a sub center and coupled to a second virtual tape device arranged in the sub center, the received data synchronized between the logical volume of the virtual tape device arranged in the main center and a logical volume of the second virtual tape device; a migration unit that performs a migration process which stores the data stored in the logical volume of the virtual tape device in the main center, in a physical volume of the first library device; an export unit that exports, when receiving an export instruction and designation of a physical volume of the second library device in the sub center from the host computer, the data stored in the logical volume of the virtual tape device in the main center, on which the migration process is completed by the migration unit, to the physical volume of the second library device via the network, so as to import the data exported in the second library device to the logical volume of the second virtual tape device for synchronization, and a volume storage unit that stores correspondence between the physical volume of the second library device and the logical volume of the virtual tape device of the main center, wherein the export unit cancels allocation of the physical volume from the volume storage unit after finishing exporting the logical volume to the physical volume of the second library device, and notifies the host computer of a completion of the exporting.