A system and method for implementing a fast file synchronization in a data processing system. A memory management unit divides a file stored in system memory into a collection of data block groups. In response to a master (e.g., processing unit, peripheral, etc.) modifying a first data block group among the collection of data block groups, the memory management unit writes a first block group number associated with the first data block group to system memory. In response to a master modifying a second data block group, the memory management unit writes the first data block group to a hard disk drive and writes a second data block group number associated with the second data block group to system memory. In response to a request to update modified data block groups of the file stored in the system memory to the hard disk drive, the memory management unit writes the second data block to the hard disk drive.