Patent ID: 8713219

Claim:
A switching device comprising: a queue number acquiring unit that acquires command queuing numbers in a plurality of storage devices that make up a virtual disk, each of the command queuing numbers indicating an upper limit of a number of process-waiting instructions that can be stored in the corresponding storage device; a selecting unit that selects a minimum value in the command queuing numbers acquired from the storage devices; a queue number setting unit that sets the selected minimum value as a command queuing number indicating an upper limit of a number of process-waiting instructions which is stored in the virtual disk; a data shifting unit that shifts data from one virtual disk to another virtual disk among virtual disks; and a modification informing unit that informs, when the shift of data is performed, a computation device that is connected to the switching device of status modification of the virtual disk that stores the data, wherein when a setting request of a command queuing number of the virtual disk to which the data is shifted is received from the computation device that receives the status modification, the queue number acquiring unit acquires a command queuing number of each of the storage devices that make up the virtual disk to which the data is shifted, the selecting unit selects a minimum value in the command queuing numbers acquired from the storage devices that make up the virtual disk to which the data is shifted, and the queue number setting unit sets the selected minimum value as the command queuing number of the virtual disk to which the data is shifted.