Method and apparatus for preemptive head crash avoidance in a disk drive

• US 6,344,938 B1
• Filed: 03/24/2000
• Issued: 02/05/2002
• Est. Priority Date: 03/24/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Smith, Gordon James
• Primary Examiner(s): FABER, ALAN
• Application Number:
  US09/535,108
• Time in Patent Office: 683 Days
• Field of Search: 360/25, 360/31, 360/75, 360/53, 360/47, 360/60, 324/212, 324/226, 714/6, 714/769, 714/770, 711/111, 711/112, 711/114, 369/53.1, 369/53.42, 369/53.45
• US Class Current: 360/25
• CPC Class Codes: G11B 21/21 with provision for maintaining desired spacing of head from record carrier, e.g. fluid-dynamic spacing, slider
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/54 with provision for moving the head into or out of its operative position or across tracks

Abstract

A method and apparatus are provided for preemptive head crash avoidance in a direct access storage device (DASD). At least two actuators are provided in the DASD. Each actuator services at least one transducer head. Monitoring for a predicted head crash is performed. Responsive to an identified predicted head crash, a transducer head for the predicted head crash is unloaded and unloading each additional transducer head being serviced by an actuator for the transducer head for the predicted head crash. A data backup process is performed. Responsive to an identified predicted head crash, data are transferred from a disk surface associated with the transducer head for the predicted head crash and transferring data from each disk surface associated with each additional transducer head being serviced by the actuator for the transducer head for the predicted head crash.

Claims

1. A method for preemptive head crash avoidance in a direct access storage device (DASD) comprising the steps of:

utilizing at least two actuators, each said actuator servicing at least one transducer head;

monitoring for a predicted head crash; and

responsive to an identified predicted head crash, unloading a transducer head for said predicted head crash and unloading each additional transducer head being serviced by an actuator for said transducer head for said predicted head crash.

2. A method for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 1 further includes the steps of responsive to an identified predicted head crash, transferring data from a disk surface associated with said transducer head for said predicted head crash and transferring data from a disk surface associated with each additional transducer head being serviced by said actuator for said transducer head for said predicted head crash.

3. A method for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 2 wherein the steps of transferring data includes the step of transferring data to a disk surface addressed by a different one of said at least two actuators than said actuator for said transducer head for said predicted head crash.

4. A method for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 2 includes the steps of checking a functionality of said transducer head for said predicted head crash and stopping data transfer responsive to an identified predefined functionality of said transducer head for said predicted head crash.

5. A method for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 2 wherein the steps of responsive to an identified predicted head crash, transferring data from a disk surface associated with said transducer head for said predicted head crash and transferring data from a disk surface associated with each additional transducer head being serviced by said actuator for said transducer head for said predicted head crash includes the step of identifying a data hierarchy for transferring said data.

7. A computer program product for preemptive head crash avoidance in a direct access storage device (DASD), said computer program product including a plurality of computer executable instructions stored on a computer readable medium, wherein said instructions, when executed by said DASD, cause the DASD to perform the steps of:

monitoring for a predicted head crash;

responsive to an identified predicted head crash, transferring data from a disk surface associated with a transducer head for said predicted head crash and transferring data from each disk surface associated with each additional transducer head being serviced by said actuator for said transducer head for said predicted head crash; and

responsive to an identified predicted head crash, unloading a transducer head for said predicted head crash and unloading each additional transducer head being serviced by an actuator for said transducer head for said predicted head crash.

6. A method for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 7 further includes the steps of utilizing a different one of said at least two actuators than said actuator for said transducer head for said predicted head crash and continuing operation of the direct access storage device (DASD).

8. A computer program product for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 7 where in the steps of transferring data includes the step of transferring data to a disk surface addressed by a different actuator than said actuator for said transducer head for said predicted head crash.

9. A computer program product for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 7 wherein the steps of transferring data includes the step of identifying a data hierarchy for transferring said data.

10. A computer program product for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 7 further includes the steps of utilizing a different actuator than said actuator for said transducer head for said predicted head crash and continuing operation of the direct access storage device (DASD).

11. Apparatus for preemptive head crash avoidance in a direct access storage device (DASD) comprising:

at least two actuators, each said actuator respectively servicing at least one transducer head;

a control unit, said control unit for monitoring for a predicted head crash;

said control unit, responsive to an identified predicted head crash, for transferring data from a disk surface associated with a transducer head for said predicted head crash and for transferring data from each disk surface associated with each additional transducer head being serviced by said actuator for said transducer head for said predicted head crash; and

said control unit, responsive to an identified predicted head crash, for unloading a transducer head for said predicted head crash and for unloading each additional transducer head being serviced by an actuator for said transducer head for said predicted head crash.

12. Apparatus for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 11 wherein said control unit, responsive to unloading said transducer heads, for utilizing a different actuator than said actuator for said transducer head for said predicted head crash and continuing operation of the direct access storage device (DASD).

13. Apparatus for preemptive head crash avoidance in a direct access storage device (DASD) as recited in claim 11 wherein said control unit, for identifying a data hierarchy for transferring said data and for transferring data to a disk surface addressed by a different actuator than said actuator for said transducer head for said predicted head crash.