Abstract: When an access request is generated from a client in a network file server comprising a computer including a communication controller connected to at least one client through a network and transferring information on a plurality of addresses inside a main storage device as one packet to at least one client, the main storage device having a buffer, a central processing unit and an input/output bus for mutually connecting the communication controller, the central processing unit and the main storage device, and a secondary storage device connected to the computer, an area for storing the data corresponding to this access request is allocated into the buffer of the main storage device. The data corresponding to the access request is read out from the secondary storage device, is transferred to the buffer and is stored in the allocated area.

Abstract: A file control method by which a number of a block first allocated to a file is saved in an external memory and data and a number of a block to be next linked or a flag indicative of an idle block are recorded in each block to thereby restore the file information, and a version of each block is recorded therein to thereby allow easy access to a data block of the specified version. A number of a head block in the file is always saved in an allocated block list of a file information area. The data and the number of the block to be next linked or the identifier indicative of an idle block are recorded in each block of the data storage area. A file control program, when it is desired to add new data to the file, allocates a spare idle block to the file. When file writing operation is interrupted, the head block number and the next block number of each block in the file information area are traced up to the idle block to thereby restore a file information table.