Patent ID: 7392362

Claim:
A volume management system comprising a storage device which has a plurality of logic areas, a computer which requests processes to the storage device, and a management server which communicates with the storage device and the computer, wherein the management server comprises a memory and a processor, the memory stores an area level indicative of released or unreleased, a priority level indicative of a priority for establishing a redundancy, a use status indicative of used or unused, and a state indicative of presence or absence of redundancies, for each of the plurality of logic areas of the storage device, and wherein when there is a logic area whose capacity is insufficient among the plurality of logic areas of the storage device, the processor of the management server determines availability of one or more released logic areas among the plurality of other logic areas of the storage device by referring to the area levels indicative of released or unreleased in the memory, when there are the one or more released logic areas, the processor allocates capacities of the one or more released logic areas to the logic area whose capacity is insufficient, when there are not enough capacities of the one or more released logic areas, the processor determines availability of one or more other unused logic areas by referring to the use statuses indicative of used or unused in the memory, when there are the one or more other unused logic areas, the processor allocates unused capacities of each of the one or more other unused logic areas to the logic area whose capacity is insufficient, and when there are not enough unused capacities of, the processor specifies one or more other logic areas whose priority levels are below a predetermined upper-limit level of the priority level indicative of a priority for establishing a redundancy by referring to the priority levels and the states indicative of presence or absence of redundancies in the memory, releases redundancies of the one or more other logic areas whose priority levels are below the predetermined upper-limit level of the priority level, and allocates released capacities of the one or more other logic areas the one or more other logic areas whose priority levels are below the predetermined upper-limit level of the priority level, to the logic area whose capacity is insufficient.