Patent ID: 8326811

Claim:
A file management method of a system including a storage device for storing a data group configuring a file as compressed data or uncompressed data, and a controller for controlling processing to be performed to the file based on a processing request from a processing request source, wherein the controller, records an access count by associating it with an area of the file if the processing request is a file access request, manages an area of the file as a split target area if the recorded access count exceeds a split threshold, splits the split target area into a plurality of partial areas at least one or more times, and, among the plurality of partial areas obtained with the split, manages the partial area in which the access count exceeded the split threshold as a non-compression target area, and manages a partial area in which the access count is less than the split threshold as a compression target area; wherein, upon transferring the file, the controller adds, to first transmission information to be transmitted as a first compressed file obtained by compressing the file, first cluster information for managing the first compressed file and sends this to a network, and stores a first dummy file including a description of the first cluster information in the storage device, wherein, upon receiving the first transmission information and the first cluster information via the network, another controller creates a second compressed file that was compressed as a second file from the first compressed file and the first cluster information belonging to the first transmission information, wherein, upon reading the second file, the controller adds, to a first transfer request of a second compressed file that was compressed as the second file, the first cluster information obtained from the first dummy file and sends this to the network, and wherein, upon receiving the first transfer request via the network, the other controller reads the second compressed file based on the first cluster information that was added to the first transfer request, and sends data of the read second compressed file, together with reply information, to the controller via the network.