Predicting failure of a magnetic tape head element

Patent metadata

Field	Value
Publication number	US-11074121-B2
Application number	US-201916358973-A
Country	US
Kind code	B2
Filing date	Mar 20, 2019
Priority date	Mar 20, 2019
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

A method, computer system, and computer program product for determining head wear of magnetic tape head elements of tape drives during operation. The method may include receiving a first calibration parameter for a first tape head element at a first time. Calibration parameter for the first tape head element may be compared with a reference parameter. Determination may be made whether to remove the first tape head element from service or generate a warning, based on a result of the comparison. Method may include generating the first calibration parameter by calculating midpoint bias voltage for the first tape head element as a function of bias current and head resistance. The first calibration parameter for the first tape head element may be bias current parameter or bias resistance parameter. The first calibration parameter for the first tape head element may be less than, equal to, or greater than the reference parameter.

First claim

What is claimed is:

1. A computer-implemented method for evaluating tape head elements, comprising:
initiating a calibration process of a cartridge mounted on a tape drive, the calibration process includes measuring a bias current and a head resistance;
generating a first calibration parameter by calculating a midpoint bias voltage for a first tape head element as a function of the bias current and the head resistance;
receiving the first calibration parameter for the first tape head element at a first time;
comparing the calibration parameter for the first tape head element with a reference parameter; and
blocking usage of the first tape head element from service based on a result of the comparison.

2. The computer-implemented method of claim 1 , further comprising:
determining whether to generate a warning regarding the first tape head element based on the result of the comparison.

3. The computer-implemented method of claim 2 , wherein:
the result of the comparison is that the first calibration parameter for the first tape head element is less than or equal to the reference parameter; and
the calibration parameter for the first tape head element is a bias current parameter.

4. The computer-implemented method of claim 2 , wherein:
the result of the comparison is that the first calibration parameter for the first tape head element is greater than or equal to the reference parameter; and
the first calibration parameter for the first tape head element is a bias resistance parameter.

5. The computer-implemented method of claim 1 , wherein the result of the comparison is that the first calibration parameter for the first tape head element is greater than or equal to the reference parameter.

6. The computer-implemented method of claim 1 , wherein the first tape head element is included in a head assembly, the head assembly including a plurality of tape head elements, further comprising removing the head assembly.

7. A computer-implemented method for evaluating a tape head element, comprising:
initiating a calibration process of a cartridge mounted on a tape drive, the calibration process includes measuring a bias current and a head resistance;
receiving a calibration parameter for a first tape head element and a first tape cartridge at a first time;
receiving a first trend for the first tape head element, wherein the first trend is determined from two or more calibration parameters for the first tape head element determined at respective times prior to the first time;
determining a second trend from the received calibration parameter for the first tape head element and the first tape cartridge, and the two or more calibration parameters for the first tape head element determined at respective times prior to the first time;
determining whether the second trend differs from the first trend by more than a first trend change parameter;
in response to determining that the second trend differs from the first trend by more than the trend change parameter, determining whether a second trend change parameter for a second tape head element is stored in a memory, the second trend change parameter being determined from a plurality of calibration parameters for the second tape head element, wherein at least one of the plurality of calibration parameters is for the second tape head element and the first tape cartridge;
in response to determining that the second trend change parameter for the second tape head element is stored in a memory, generating a warning regarding the first tape cartridge.

8. The computer-implemented method of claim 7 , further comprising:
determining whether a third trend change parameter for a third tape head element is stored in a memory, the third trend change parameter being determined from a plurality of calibration parameters for the third tape head element, wherein at least one of the plurality of calibration parameters is for the third tape head element and the first tape cartridge;
in response to determining that the third trend change parameter for the third tape head element is stored in a memory, preventing the first tape cartridge from use.

9. A system for evaluating a tape head element, comprising:
a computer system comprising, a processor, a computer readable storage medium, and program instructions stored on the computer readable storage medium being executable by the processor to cause the computer system to:
initiate a calibration process of a cartridge mounted on a tape drive, the calibration process includes measuring a bias current and a head resistance;
generate a first calibration parameter by calculating a midpoint bias voltage for a first tape head element as a function of the bias current and the head resistance;
receive the first calibration parameter for the first tape head element at a first time;
compare the calibration parameter for the first tape head element with a reference parameter; and
block usage of the first tape head element from service based on a result of the comparison.

10. The system of claim 9 , further comprising:
determining whether to generate a warning regarding the first tape head element based on the result of the comparison.

11. The system of claim 10 , wherein:
the result of the comparison is that the first calibration parameter for the first tape head element is less than or equal to the reference parameter; and
the calibration parameter for the first tape head element is a bias current parameter.

12. The system of claim 10 , wherein:
the result of the comparison is that the first calibration parameter for the first tape head element is greater than or equal to the reference parameter; and
the calibration parameter for the first tape head element is a bias resistance parameter.

13. The system of claim 9 , wherein the result of the comparison is that the first calibration parameter for the first tape head element is greater than or equal to the reference parameter.

14. The system of claim 9 , wherein the first tape head element is included in a head assembly, the head assembly including a plurality of tape head elements, further comprising removing the head assembly.

Assignees

• IBM

Inventors

• Breuer Marcus
• Krick Frank
• Oswald Tim
• Freitag Bernd

Classifications

• G06F11/0793 Primary

  Remedial or corrective actions (recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40) · CPC title

• G11B5/5534

  Initialisation, calibration, e.g. cylinder "set-up" · CPC title

• G06F11/0751

  Error or fault detection not based on redundancy (power supply failures G06F1/30; network fault management H04L41/06) · CPC title

• G06F11/0727

  in a storage system, e.g. in a DASD or network based storage system (drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097) · CPC title

• G11B5/3189 Primary

  Testing · CPC title