Patent ID: 8112463

Claim:
A file management method in a storage system that includes a first file server having a first storage area, a second file server which is coupled to the first file server and which includes a second storage area, and one or more computers coupled to the first and second file servers, the method comprising: the computer splitting a data array stored in one file into one or more fragment data arrays including a first fragment data array; the first file server storing a first fragment file that stores the first fragment data array in the first storage area; the computer splitting a data array stored in a second file into one or more fragment data arrays including a second fragment data array; the second file server storing a second fragment file that stores the second fragment data array in the second storage area; and the first file server, if the first fragment data array matches the second fragment data array, deleting the first fragment data array, and changing the first fragment file to a stub that indicates the second fragment data array, wherein the first file server, in a case where a request to write data to the stub is received from the computer, changes the stub to a third fragment file, stores a copy of the second fragment data array in the third fragment file, and stores the data for which writing has been requested by the computer in a third fragment data array stored in the third fragment file.