Patent ID: 7447838

Claim:
A computer readable medium storing a virtual storage management program, said virtual storage management program causing a computer to execute: a capacity designation designating the capacity of virtual volumes; a first selection selecting one (1) or a plurality of physical volumes which satisfy the designated capacity from a pool which registers the physical volumes such that the number of selected physical volumes is minimized and assigning the selected physical volumes to the virtual volumes; a second selection selecting one (1) or a plurality of physical volumes which satisfy the designated capacity such that the number of extents is minimized which is the number of unassigned areas dispersed in the selected physical volumes and assigning the selected physical volumes to the virtual volumes if the selection is unsuccessful at the first selection, wherein the first selection comprises: a first priority selection selecting an extent having an available capacity which is equal to or larger than the designated capacity and which is the minimal capacity; a second priority selection selecting a physical volume having an available capacity which is equal to or larger than the designated capacity and which is the minimal capacity if the selection is unsuccessful at the first priority selection; and a third priority selection selecting a physical volume having an available capacity which is smaller than the designated capacity and which is the maximal capacity if the selection is unsuccessful at the second priority selection.