A method of allocating storage areas, intended to reserve the storage areas formed on a storage device for storing data, this method including the steps of: registering beforehand as a storage configuration information table 105, information on multiple storage areas to be managed and on the position where the storage device is installed; registering information on the purposes of use and positions of the storage areas beforehand as a position management table 107; acquiring position information from the position management table 107 in accordance with an allocation request for a storage area associated with the purpose of use; selecting an unallocated storage area from the storage configuration information table 105 with reference to the position information; and sending information on a selected area to a client from which the allocation request was issued.