A working method for a mass storage system includes providing a virtual file system for at least one user of the mass storage system; determining an access probability for files stored logically in the virtual file system, storing distributed files whose access probability lies above a predetermined limit value in a plurality of first physical mass storage devices which are independent of one another and have read/write units independent of one another and storing combined files whose access probability lies below the predetermined limit value in at least one contiguous storage region of at least one second physical mass storage device.