File server that allows an end user to specify storage characteristics with ease

A file server device is provided which has less chance of error in changing directory settings information. A file server device that has access to a client computer and a disk array device receives a directory settings file, and writes the directory settings file in a specified shared directory. The file server device chooses, as a migration destination candidate, a volume whose settings information matches new settings information of the shared directory which is set as specified in the directory settings file. The file server device migrates information in the shared directory whose settings information is changed to the volume chosen as a migration destination candidate.