A method is provided for sharing a file among a plurality of hosts; the file is stored in a disk device shared among the plurality of hosts, each of which uses an operating system (OS) having a different format. In general, a management system of a file is different depending on the OS. Therefore, because a stored location of the file is unknown, it is not possible to view the file, which is managed by a management system of a certain OS, from the other OSs. Therefore, a method is provided whereby stored-location information of the file, which is managed by a management system of a first OS, is converted into stored-location information that is managed by a second OS format. Then, the second OS reads the file on the basis of the stored-location information that has been converted.