A method and system for providing intercommunication of I/O access factors between a file system and device driver, described as follows. A factor data block is provided which stores I/O access factors used by a file system and a device driver. The file system performs application program requests to access files by providing appropriate file system requests to the device driver based on the I/O access factors. The device driver performs the file system requests by controlling access to an appropriate peripheral device based on the I/O access factors. In a preferred embodiment, the I/O access factors include real time status data indicating a current status of I/O processing. The I/O access factors also include device constraint data indicating limitations of the peripheral devices. During an I/O access, the file system reads the real time status data and device constraint data and performs an application program request based on the real time status data and device constraint data, passing a file system request to the device driver. The device driver reads the real time status data and performs the file system request based on the real time status data.