Patent ID: 7222168

Claim:
A computer system comprising a plurality of computers, a plurality of file servers connected to said computers via a network, a management server connected to said computers and said file servers via said network, a backup server connected to said management server off said network, and a storage system connected to said file servers and said management server off said network, with said storage system comprising a plurality of storage devices and a storage controller which controls said plurality of storage devices, wherein: each of said file servers manages a respective file system having a directory structure, stores a first program, and has a first CPU which executes said first program; said management server manages a file system having a directory structure, stores a second program, and has a second CPU which executes said second program, wherein the file system managed by the management server includes the respective file systems managed by the plurality of file servers; said second program comprises: a part for making a request to one of said file servers via said network for information necessary for said management server to back up a file to said backup server as a backup object, said file being stored in said storage system and logically set with a path to said requested file server when said request is made; said first program comprises: a part which responds to said request by sending said management server, via said network, an identifier of a second storage device in said storage system that stores duplicate data of said file; and said second program further comprises: a part which makes a determination, based on said identifier received from the requested file server, whether the requested file server manages the file system having the file to be backed up according to the request; a part which notifies the requested file server that backup of the file to be backed up will be performed, if the determination is that the requested file server manages the file system having the file to be backed up; a part which obtains backup data from said duplicate data from said second storage device off said network, based on said identifier; and a part which sends the obtained backup data to said backup server off said network.