Abstract: In a hard disk drive where data is read from and written to a magnetic disk by a magnetic head in accordance with a command from a host computer, a moving distance of the magnetic head in a radial direction is detected within a predetermined period of time. The magnetic head is moved for seeking by a predetermined distance when the moving distance detected is small. The system and method of the present invention reduces write failures due to the undulation of a lubricant film on the magnetic disk by effectively preventing undulation.

Abstract: In a hard disk drive where data is read from and written to a magnetic disk by a magnetic head in accordance with a command from a host computer, a moving distance of the magnetic head in a radial direction is detected within a predetermined period of time. The magnetic head is moved for seeking by a predetermined distance when the moving distance detected is small. The system and method of the present invention reduces write failures due to the undulation of a lubricant film on the magnetic disk by effectively preventing undulation.

Abstract: The present invention relates to controlling the flying height of a magnetic head or slider relative to a magnetic disk in a disk storage device. The flying height of the negative pressure slider is not affected by changes in temperature. By controlling a ratio of crown sensitivity of the flying height to camber sensitivity of the flying height, changes in flying height due to the crown change of the slider corresponding to temperature changes are canceled. It is necessary to set a ratio of the area of a reverse step surface, R, to the area of a center rail, C, within a range of 2:1 to 6:1 (preferably 4:1 to 6:1; ideally 5:1). Then, setting can be performed so that the center of the substantially negative pressure generated may be the center of the slider surface.

Abstract: To provide a lubricant supply being capable of supplying adequate lubricant over a long period in a magnetic disk unit comprising a lubricant supply to reduce friction between a magnetic disk and magnetic head. A unit of the invention can supply lubricant uniformly to a magnetic disk, and easily controls supply volume. This comprises a material impregnated with lubricant having sufficient lubricant to supply over a long period, a thin film to supply predetermined lubricant to a disk surface, the film permeable by lubricant from the material impregnated with lubricant, and a clamp assembly to fix the material impregnated with lubricant and the thin film to the disk. The thin film is fixed on the disk and compressed by a compression part formed at the edge of the clamp assembly. The degree of compression controls lubricant supply to the disk.