Patent ID: 7305536

Claim:
A computer system comprising: a storage system; a host computer connected to the storage system via a network; and a management computer connected to the storage system, wherein the storage system comprises a first interface connected to the network, a first processor connected to the first interface, a first memory connected to the first processor, and a disk drive where data written by the host computer is stored, wherein the host computer comprises a second interface connected to the network, a second processor connected to the second interface, and a second memory connected to the second processor, wherein the management computer comprises a third interface connected to the storage system, a third processor connected to the third interface, and a third memory connected to the third processor, wherein the second processor recognizes a storage area of the disk drive on a logical volume basis, wherein the first processor measures, for each logical volume, a storage capacity of the logical volume and a used I/O amount of the logical volume, which indicates a amount of a I/O resource used by the logical volume, and wherein the third processor has the following functions: manages the logical volumes in groups by storing the association relation between the logical volumes and groups in the third memory; obtains, via the third interface, the used I/O amount of the logical volume and storage capacity of the logical volume measured by the first processor; designates to a logical volume to which data is to be moved based on a ratio of the obtained used I/O amount of the logical volume to the obtained storage capacity of the logical volume; and instructs, via the third interface, the first processor to move data from the data's original logical volume to the logical volume designated as the destination of migration.