Buffer management system and its method

PURPOSE: To improve the hit rate of a read access to a file server by means of a client and to manage a file server buffer. CONSTITUTION: Related files are grouped in file sets, and file access operation (namely, reading/writing) statistics for the respective file sets are collected. The file sets are classified into plural file set classifications having similar and collected access operation statistics. Different file server buffer management policies are implemented on blocks (or pages) from the different file set classifications. Thus, a purpose is accomplished. In the buffer management policy applied to the classifications, the file block (or page) having the high read/write rate in general is designed to have high priority in general and it is stored in a file server buffer.