Patent ID: 8230191

Claim:
A computer-readable recording medium encoded with an allocation control program containing instructions executable on a computer, the allocation control program dispersedly arranging a logical volume in a plurality of storage apparatuses, the program causing the computer to execute an operation, the operation comprising: a logical volume generation procedure including: allocating logical volume divided areas obtained by dividing the logical volume to real storage areas provided with a data storage area in a physical storage area of a storage apparatus group, setting management information in which identification information of the allocated real storage areas is associated with identification information of the logical volume divided areas to be stored in a storage section, allocating, at a time of duplicating the logical volume, duplicate logical volume divided areas obtained by dividing a generated duplicate logical volume to virtual storage areas which do not have the data storage area in the physical storage area of the storage apparatus group, associating identification information of the allocated virtual storage areas, the identification information of the duplicate logical volume divided areas, and identification information of duplication source logical volume divided areas corresponding to the duplicate logical volume divided areas to be set in the management information, and sending the management information to a storage management apparatus for managing an allocated virtual storage area; and a reallocation procedure including: detecting, when a data writing request to the duplicate logical volume divided area to which the virtual storage area is allocated occurs, based on the management information stored in the storage section, an unallocated area real storage area in the logical volume divided areas or the duplicate logical volume divided areas, reallocating the real storage area to the duplicate logical volume divided area where the writing request occurs to update the management information, identifying, based on the management information, the real storage area allocated to the duplication source logical volume divided area corresponding to the duplicate logical volume divided area, and copying data stored in the real storage area to the real storage area allocated to the duplicate logical volume divided area.