A method of managing data of a file system using a database management system is provided. According to the method, the metadata of the file system is managed using a database management system (DBMS), but writing data to or reading data from a disk is directly performed by the file system according to the method directly performed not through other file systems or DBMSs. In this way, stable transactions are guaranteed for a user, and the user can design a disk allocation algorithm optimized with respect to a multimedia environment.