Patent ID: 8290992

Claim:
A file management method comprising: creating a rotation group by grouping a file group in which generations of files are managed by a change in file names, and storing information of the rotation group in a rotation group management unit; acquiring file identification information of files belonging to the rotation group from the file group according to the information of the rotation group, and storing the file identification information in a file identification information management unit; acquiring file identification information of the rotation group from the file identification information management unit, further acquiring file identification information of the files belonging to the rotation group from the file group according to the information of the rotation group, and comparing the file identification information further acquired from the file group with the file identification information acquired from the file identification information management unit; and upon receiving a copy request in a rotation group unit, copying the files belonging to the rotation group of a copy object to a copy destination, and performing a comparison between the file identification information further acquired from the file group and the file identification information acquired from the file identification information management unit in parallel with the copying, wherein copying of the files belonging to the rotation group is retried according to a result of the comparison between the file identification information further acquired from the file group and the file identification information acquired from the file identification information management unit.