A method for controlling a hard disk drive, includes a track seeking servo routine in which seek time is measured in a mode of the routine after the trajectory mode, the measured seek time is compared with a predetermined period of time, and an alarm mode is induced when the measured seek time exceeds the predetermined period of seek time. It exhibits upright growth with abundant flowers. When needed, the effects of an operation are stored in the thread interface frame, allowing the effects to be forwarded to another subhierarchy accessed by another thread. The device may move along the length of the feed rail, as well.