1. A method for exercising file storage destination volume control in a file system in which data are selectively stored on a plurality of volumes in compliance with a file storage request from a business application, said method comprising: a storage requirement calculation step for calculating reliability requirements or performance requirements which are the storage requirements for a specific file for requested storage; a storage destination volume selection step for selecting an actual file storage destination volume in accordance with the calculated storage requirements and the reliability characteristics or performance characteristics of each volume; and a file storage step for storing the file on the selected storage destination volume.