A method of achieving ion beam uniformity control using ion beam blockers. A controlling device has the ability to cancel a pending notify command, by sending a cancelling command to a target device while the notify command is pending. In use, tape is adhered to the exterior surface of the main body member at the plurality of apertures. The sheath is axially movable relative to the catheter to selectively uncover at least a portion of the infusion ports and thereby control the amount and distribution of the infusate delivered by the infusion section. The storage system can detect that a write issued by the file system was lost by one of the functional layers that provide the data storage path between the file system and the mass storage media.