Storage device, continuous-vibration detecting method, and control apparatus
AssigneeFujitsu Limited
InventorsTakahiro Aoki, Takeshi Hara, Shigenori Yanagi
Life of this patent
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Abstract
A falling-time measuring unit acquires information indicating whether a magnetic disk drive is falling, from a fall sensor at a predetermined sampling cycle, and measures a falling time based on the acquired information. A threshold changing unit counts number of times the measured falling time exceeds a predetermined fall-determination threshold within a predetermined time, and extends the fall-determination threshold when the counted number of times exceeds a predetermined maximum number of times. A head retracting unit retracts the head to the retraction position when the measured falling time exceeds the extended fall-determination threshold.
Claims20
A storage device that retracts a head on a storage medium to a predetermined retraction position upon detecting a fall, the storage device comprising:
- a falling-time measuring unit that acquires information indicating whether the magnetic disk drive is falling, from a fall sensor at a predetermined sampling cycle, and measures a falling time based on the acquired information;
- a threshold changing unit that counts number of times the measured falling time exceeds a predetermined fall-determination threshold within a predetermined time, and extends the fall-determination threshold when the counted number of times exceeds a predetermined maximum number of times;
- and
- a head retracting unit that retracts the head to the retraction position when the measured falling time exceeds the extended fall-determination threshold.
A continuous-vibration detecting method for a storage device that retracts a head on a storage medium to a predetermined retraction position upon detecting a fall, the continuous-vibration detecting method comprising:
- falling-time measuring including
- acquiring information indicating whether the magnetic disk drive is falling, from a fall sensor at a predetermined sampling cycle;
- and
- measuring a falling time based on the acquired information;
- threshold changing including
- counting number of times the measured falling time exceeds a predetermined fall-determination threshold within a predetermined time;
- and
- extending the fall-determination threshold when the counted number of times exceeds a predetermined maximum number of times;
- and
- retracting the head to the retraction position when the measured falling time exceeds the extended fall-determination threshold.
A computer program product comprising a computer usable medium having computer readable program codes embodied in the medium that when executed causes a computer to execute:
- falling-time measuring including
- acquiring information indicating whether the magnetic disk drive is falling, from a fall sensor at a predetermined sampling cycle;
- and
- measuring a falling time based on the acquired information;
- threshold changing including
- counting number of times the measured falling time exceeds a predetermined fall-determination threshold within a predetermined time;
- and
- extending the fall-determination threshold when the counted number of times exceeds a predetermined maximum number of times;
- and
- retracting the head to the retraction position when the measured falling time exceeds the extended fall-determination threshold.
A control apparatus that controls a storage device that retracts a head on a storage medium to a predetermined retraction position upon detecting a fall, the control apparatus comprising:
- a falling-time measuring unit that acquires information indicating whether the magnetic disk drive is falling, from a fall sensor at a predetermined sampling cycle, and measures a falling time based on the acquired information;
- a threshold changing unit that counts number of times the measured falling time exceeds a predetermined fall-determination threshold within a predetermined time, and extends the fall-determination threshold when the counted number of times exceeds a predetermined maximum number of times;
- and
- a head retracting unit that retracts the head to the retraction position when the measured falling time exceeds the extended fall-determination threshold.
Dependencies are inferred from the claim text.