Patent ID: 8037276

Claim:
A storage system coupled to a plurality of host computers comprising: a plurality of physical disks storing data; a plurality of controllers, each controller corresponding to a respective physical disk of the plurality of physical disks; and a server controlling access from the plurality of host computers to the plurality of physical disks, wherein the server acquires volume allocation information which indicates a relation between a plurality of logical volumes provided to the plurality of host computers and storage areas in the plurality of physical disks, and physical disk information which indicates a relation between the storage areas and the plurality of physical disks, wherein the server creates a plurality of volume groups, each of the plurality of volume groups including one or more logical volumes of the plurality of logical volumes, wherein the server sets a first physical disk of the plurality of physical disks to a first volume group of the plurality of volume groups as a priority physical disk, the first volume group including a plurality of first logical volumes of the plurality of logical volumes and having a least remaining capacity among the plurality of volume groups, wherein the server sets a plurality of first storage areas included in the first physical disk to each of the plurality of first logical volumes included in the first volume group as priority allocation storage areas, wherein when the controller receives a write request for writing to one of the plurality of first logical volumes of the physical disk corresponding to the controller, the controller confirms whether a storage area is not allocated to the one of the plurality of first logical volumes, and if a storage area is not allocated to the one of the plurality of first logical volumes, the controller allocates a storage area of the priority allocation storage areas to the one of the plurality of first logical volumes, and writes data corresponding to the write request to the allocated storage area, wherein the server creates each of the plurality of volume groups by grouping together logical volumes that share a physical disk based on the volume allocation information and the physical disk information, wherein the server confirms whether a second disk drive of the plurality of disk drives is allocated to each of a plurality of second volume groups of the plurality of volume groups as a priority physical disk, and wherein if the second disk drive is allocated to each of the plurality of second volume groups as a priority physical disk, the server integrates a plurality of second volume groups into a new volume group.