Patent ID: 6892203

Claim:
A remote file sharing method used for a remote file-sharing system, said remote file-sharing system comprising: a first computer system in which a first higher-level device and a first file input/output device are connected to each other via a first network; and a second computer system in which a second higher-level device and a second file input/output device are connected to each other via said first network; wherein said first file input/output device and said second file input/output device are connected to each other via a second network; in response to a data write request from said first higher-level device, data is written into a storage medium in said first file input/output device, and said data is remotely double-recorded into a storage medium in said second file input/output device via said second network; and files stored in both of said first file input/output device and said second file input/output device are shared between said first higher-level device and said second higher-level device; said method comprising the steps of: receiving, by said first file input/output device, said data write request with specification of a specific file, setting read/write exclusive control information in a table means, for said specific file, at a value indicating an exclusive state if the read/write exclusive control information does not indicate an exclusive state, and specifying said specific file to request said second file input/output device, via said first network, to put said specific file into an exclusive state; setting read/write exclusive control information in a table means corresponding to said table means, for said specific file, at a value indicating an exclusive state by said second file input/output device if the read/write exclusive control information does not indicate an exclusive state, and reporting to said first file input/output device that the exclusion setting has been successfully completed; after writing of said data into the storage medium in said first file input/output device and the remote double recording by said first file input/output device have been completed, releasing the exclusive state of the exclusive control information for said specific file in said table means, and requesting said second file input/output device to release the exclusive state of said specific file; and releasing the exclusive state of the exclusive control information for said specific file by said second file input/output device.