Abstract: A network address management unit (210) allocates, to the first edge node, a first network address (500) on which a physical configuration of a first edge node (100a) is reflected. The network address management unit, when a second edge node (100b) is coupled to the first edge node, allocates, to the first edge node, a second network address (510) on which the physical configuration of the first edge node is reflected with respect to the second edge node. When the first edge node receives a packet that designates the first or second network address as a destination network address, the first edge node, based on the destination network address designated by the received packet, determines whether the received packet is transferred to the second edge node and discriminates a transfer destination path in the first edge node.

Abstract: There is provided an autonomous distributed type file system which is connected to a data reference device through a first network. The autonomous distributed type file system includes a plurality of storage device units which are mutually connected through a second network and are connected to the first network. Each of the storage device unit includes a local storage and a local controller. The local controller includes a storage directory and a duplicated data maintaining unit. The duplicated data maintaining unit refers to the storage directory, and continuously keeps same contents of duplicated data items in a range without running out of storage capacity of an own node. When there is no free space in the storage capacity, duplicate writing of the data with the same contents is prevented.