Storage apparatus, method of detecting failure in head of storage apparatus, and storage medium storing failure detection program
View Patent ↗According to one embodiment, a storage apparatus includes: a read section that receives a predetermined electrical parameter to read out data from a recording medium; a characteristic detection section that detects a plurality of characteristic values corresponding to a plurality of different predetermined electrical parameters received by the read section, respectively, the characteristic values being predetermined indicators of the read section, respectively; a characteristic relation acquisition section that acquires a slope of a characteristic value versus a predetermined electrical parameter from the predetermined electrical parameters and the characteristic values; and a determination section that determines presence/absence of failure in the read section based on the slope acquired by the characteristic relation acquisition section.
1. A magnetic disk drive comprising:
a magnetic head that receives a predetermined bias voltage to read out data from a recording medium;
a characteristic detection section that detects a plurality of Viterbi Trellis Margins (VTMs) corresponding to a plurality of different bias voltages received by the magnetic head, respectively, the VTMs being a predetermined indicator of the magnetic head and being a value indicating an error rate in the bias voltage in a simple manner;
a characteristic relation acquisition section that acquires a slope of correlation between the bias voltages and the VTMs; and
a determination section that determines presence/absence of failure in the magnetic head based on the slope acquired by the characteristic relation acquisition section.
2. The magnetic disk drive according to claim 1 , wherein the determination section quantifies the slope acquired by the characteristic relation acquisition section and determines that failure has occurred in the read section in the case where the quantified slope exceeds a predetermined threshold value.
3. The magnetic disk drive according to claim 1 , wherein:
the characteristic detection section detects the characteristic values over time as well as the characteristic relation acquisition section acquires the slope over time based on the characteristic values detected over time, and
the characteristic relation acquisition section determines presence/absence of failure in the read section based on a change over time in the slope.
4. The magnetic disk drive according to claim 1 , wherein the slope is obtained at a plurality of measurement points.
5. The magnetic disk drive according to claim 4 , wherein a portion of slopes obtained at the measurement points is used as the slope.
6. The magnetic disk drive according to claim 4 , wherein an average of slopes obtained at the measurement points is used as the slope.
7. The magnetic disk drive according to claim 1 , wherein a change in the slope is used as the slope.
8. The magnetic disk drive according to claim 1 , wherein the read section is a tunnel effect type reproducing head.
9. The magnetic disk drive according to claim 1 , wherein the VTMs are a value defined by counts obtained in a case where a difference between metric values associated with the two paths falls below a given threshold value.
10. A method of detecting a failure in a head of a magnetic disk drive, comprising:
a read step that gives a plurality of different predetermined bias voltages to a magnetic head to read out data from a recording medium using the magnetic head;
a characteristic detection step that detects Viterbi Trellis Margins (VTMs) corresponding to the bias voltages, respectively, the VTMs being a predetermined indicator of the magnetic head and being a value indicating an error rate in the bias voltage in a simple manner;
a characteristic relation acquisition step that acquires a slope of correlation between the bias voltages and the VTMs; and
a determination step that determines presence/absence of failure in the magnetic head based on the slope acquired by the characteristic relation acquisition step.
11. The method of detecting a failure in a head of a storage apparatus according to claim 10 , wherein the determination step quantifies the slope acquired by the characteristic relation acquisition step and determines that failure has occurred in the head in the case where the quantified slope exceeds a predetermined threshold value.
12. The method of detecting a failure in a head of a storage apparatus according to claim 10 , wherein
the characteristic detection step detects the characteristic values as well as the characteristic relation acquisition step acquires the slope over time based on the characteristic values detected over time, and
the characteristic relation acquisition step determines presence/absence of failure in the head based on a change over time in the slope.
13. The method of detecting a failure in a head of a storage apparatus according to claim 10 , wherein a change in the slope is used as the slope.
14. The method of detecting a failure in a head of a storage apparatus according to claim 10 , wherein the VTMs are a value defined by counts obtained in a case where a difference between metric values associated with two paths falls below a given threshold value.
15. A computer-readable non-transitory storage medium storing therein a computer program for a magnetic disk drive that detects a failure in a magnetic head of the magnetic disk drive, the computer program causing a computer to execute:
a read step that gives a plurality of different predetermined bias voltages to a magnetic head to read out data from a recording medium using the magnetic head;
a characteristic detection step that detects Viterbi Trellis Margins (VTMs) corresponding to the bias voltages, respectively, the VTMs being a predetermined indicator of the magnetic head and being a value indicating an error rate in the bias voltage in a simple manner;
a characteristic relation acquisition step that acquires a slope of correlation between the bias voltages and the VTMs; and
a determination step that determines presence/absence of failure in the magnetic head based on the slope acquired by the characteristic relation acquisition step.
16. The computer-readable non-transitory storage medium according to claim 15 , wherein the determination step quantifies the slope acquired by the characteristic relation acquisition step and determines that failure has occurred in the head in the case where the quantified slope exceeds a predetermined threshold value.
17. The computer-readable non-transitory storage medium according to claim 15 , wherein:
the characteristic detection step detects the characteristic values over time as well as the characteristic relation acquisition step acquires the slope over time based on the characteristic values detected over time, and
the characteristic relation acquisition step determines presence/absence of failure in the head based on a change over time in the slope.
18. The computer-readable non-transitory storage medium according to claim 15 , wherein the VTMs are a value defined by counts obtained in a case where a difference between metric values associated with two paths falls below a given threshold value.