Patent ID: 7426619

Claim:
An inter-volume migration system, comprising: a storage subsystem having one or more volumes; an inter-volume relocation instruction module that relocates a relocation-source volume to a relocation-destination volume for copy data stored in the relocation-source volume; a cost calculation module that calculates a cost of a volume; and a volume selection module that selects a candidate for the relocation-destination volume, whose cost is within an upper limit and lower limit of the cost per unit capacity, based on the cost of the volume calculated by the cost calculation module and constraints imposed on the relocation-destination volume; a constraint pre-registration module that previously registers the constraints to be imposed on the relocation-destination volume in association with the relocation-source volume; and a processing module that executes an inter-volume relocation processing, wherein the processing module obtains the constraints relating to the relocation-source volume from among the constraints previously registered by the constraint pre-registration module, wherein the volume selection module selects the candidate for the relocation-destination volume whose size is larger than the relocation-source volume size and which is unused, based on the constraints obtained by the processing module, and wherein the cost calculation module calculates the cost of the volume based on a chronological variation of a unit price of at least one disk including the volume.