Patent ID: 7644242

Claim:
A control device of a storage system that comprises a plurality of each of storage devices of a plurality of types including storage devices of a first type and a second type, comprising: a memory; and a CPU coupled to the memory, wherein the CPU acquires an archive deadline of archive target data which are the target of archiving by the storage system, wherein the CPU acquires a warranty deadline for the quality of data stored by the storage device and unit costs constituting the costs for a predetermined storage size of the storage device, for each of the storage devices of the plurality of types, wherein the CPU acquires data migration costs constituting the costs required for data migration from a certain storage device among the storage devices of the plurality of types to another storage device among the storage devices of the plurality of types, wherein the CPU selects a storage device constituting the storage destination of the archive target data from the storage devices of the plurality of types on the basis of the archive deadline, warranty deadline, unit cost and data migration cost thus acquired, wherein the selected storage device is a storage device of a type for which the total cost when the archive target data are archived until the warranty deadline is minimum, and the total cost is a cost that is obtained from a first cost obtained from the product of the number of data migrations and the data migration cost, a unit cost of a data migration source, and a unit cost of a data migration destination.