Abstract: A device input/output ("I/O") monitoring mechanism serving as an interface between a computer operating system kernel and a device driver which obviates the necessity of implementing specific pseudo-device drivers for various peripheral devices and provides a standard interface between, for example, computer mass storage devices and a computer operating system. The I/O monitoring mechanism disclosed is of especial utility in the measurement of general storage device I/O performance and allows I/O statistics to be presented to application-level software operating in conjunction with a computer operating system which facilitates the identification of storage device "hot spots" within metadevices and sub-metadevices. The mechanism of the present invention is usable across a wide range of storage device peripheral hardware and device drivers and allows user-level program code to readily determine the associated physical sub-component.