Patent ID: 8145687

Claim:
A file detection device, included in a network node controller, for detecting a specified file among a plurality of files stored in a storage device, comprising: an access history management unit for managing an access history of a client with respect to individual files that constitute the plurality of files; and a file detection unit for detecting a file, which is accessed between a time when a corresponding user logs into the storage device and a time when any of the plurality of files is updated on the basis of information of the access history, as a reference source candidate for the updated file, wherein the access history management unit receives a file access request from the client and provides the client with file access services that provide the client with a file designated by the file access request among the plurality of files stored in the storage device, wherein the network node controller constitutes a network connection storage device together with the storage device, and wherein the network node controller is connected to the client via a network.