A file system includes a plurality of information-processing-devices, a plurality of storage devices and a management device, each connected to a communications network, wherein each information processing devices includes a transmission unit for transmitting state information indicating utilization state of the communications network by the information-processing-device to the management device, and the management device includes a determination unit for determining an information-processing-device to execute an inputted job, and a first storage device, and further determine a first path in the communications network for the information-processing-device to access to the first storage device, a collection unit for collecting the state information, and an alteration unit configured to identify, based on the collected state information, a second storage device enhancing access efficiency and a second path in the communications network enhancing access efficiency, and alter the first storage device and the first path to the second storage device and the second path.