Patent ID: 8316205
Filing Date: 2012-11-20
Classification: G06F

Abstract:
1. A method for copying data in a storage system, the storage system comprising a host computer, a first storage apparatus coupled to the host computer, a second storage apparatus coupled to the first storage apparatus, the first storage apparatus comprising a first plurality of disks for storing data and a first controller for controlling the storage of data in the first plurality of disks, and the second storage apparatus comprising a second plurality of disks for storing data and a second controller for controlling the storage of data in the second plurality of disks, the method comprising: providing, by the first controller, a first virtual volume, which is defined by a plurality of virtual areas, to the host computer; allocating, by the first controller, a storage area of the first plurality of disks to a virtual area of the plurality of virtual areas in accordance with a write request; managing, by the first controller, information indicating whether or not the storage area is allocated to each of the plurality of virtual areas; a determining step for determining whether or not the storage area is allocated to a first virtual area of the plurality of virtual areas when an initial copy of the first virtual volume to the second storage apparatus is executed; and a sending step for sending data stored in the first virtual area to the second storage apparatus if the storage area is allocated to the first virtual area, wherein the first controller is configured to send a notice to the second controller of the second storage apparatus, the notice indicating that data to be stored in the second virtual area is not included, if the storage area is not allocated to the first virtual area, and wherein when the second controller receives the notice, the second controller is configured to not allocate the storage area to the second virtual area if the storage area is not allocated to the second virtual area, and write zero data to the second virtual area if the storage area is allocated to the second virtual area.