Granted Patent B1

US 8,843,779 · App. 13/612,743 · Granted Sep 23, 2014

Abstract

Claims (47)

1. A disk drive comprising:

a disk surface comprising a first backup location, and a second backup location;

a head actuated radially over the disk surface to write data to the disk surface;

a memory configured to store a signature, wherein the signature comprises a running number; and

control circuitry coupled to the head, the control circuitry configured to:

receive a command to write data to the disk surface;

insert the signature into the data;

write the data to the disk surface;

alternately write a spare copy of the data to the first backup location and to the second backup location based on a value of the signature; and

write the spare copy of the data to the first backup location when the running number is an odd number, and write the spare copy of the data to the second backup location when the running number is an even number.

2. The disk drive of claim 1 wherein the memory is further configured to store an electronic file management table.

3. The disk drive of claim 2 wherein the electronic file management table stores an indication of the running number corresponding to the data, and an indication of whether the data written to the disk surface, or the spare copies of the data written to the first backup location or the second backup location, contains errors.

4. The disk drive of claim 1 wherein the control circuitry is further configured to increment the running number when the data is successfully written to the disk surface.

5. The disk drive of claim 1 wherein the control circuitry is further configured to:

determine whether the data written to the disk surface, or the spare copy of the data written to the first backup location or the second backup location contains errors;

set the second backup location to a read-only status when the running number is an odd number and the data written to the disk surface or the spare copy of the data written to the first backup location contains errors; and

set the first backup location to a read-only status when the running number is an even number and the data written to the disk surface or the spare copy of the data written to the second backup location contains errors.

6. The disk drive of claim 5 wherein the control circuitry is further configured to:

replace the data written to the disk surface with the spare copy of the data written to the first backup when the spare copy of the data written to the second backup location contains an error; and

replace the data written to the disk surface with the spare copy of the data written to the second backup location when the spare copy of the data written to the first backup location contains an error.

7. The disk drive of claim 1 wherein the disk surface further comprises a first working location and a second working location, and wherein the control circuitry is further configured to write the data to the first working location when the running number is an odd number, and write the data to the second working location when the running number is an even number.

8. The disk drive of claim 7 wherein the control circuitry is further configured to:

determine whether the data written to the first working location or the second working location, or the spare copy of the data written to the first backup location or the second backup location contains errors;

set the second working location and the second backup location to a read-only status when the running number is an odd number, and the data written to the first working location or the spare copy of the data written to the first backup location contains errors; and

set the first working location and the first backup location to a read-only status when the running number is an even number, and the data written to the second working location or the spare copy of the data written to the second backup location contains errors.

9. A method for backing up data in a data storage device comprising a disk surface comprising a first backup location, and a second backup location, a head actuated radially over the disk surface to write data to the disk surface, a memory configured to store a signature, wherein the signature comprises a running number, and control circuitry coupled to the head, the method comprising:

receiving a command to write data to the disk surface;

inserting the signature into the data;

writing the data to the disk surface;

alternately writing a spare copy of the data to the first backup location and to the second backup location based on a value of the signature; and

writing the spare copy of the data to the first backup location when the running number is an odd number, and writing the spare copy of the data to the second backup location when the running number is an even number.

10. The method of claim 9 further comprising storing an electronic file management table in the memory.

11. The method of claim 10 further comprising storing in the electronic file management table an indication of the running number corresponding to the data, and an indication of whether the data written to the disk surface, or the spare copies of the data written to the first backup location or the second backup location, contains errors.

12. The method of claim 9 further comprising incrementing the running number when the data is successfully written to the disk surface.

13. The method of claim 9 further comprising:

determining whether the data written to the disk surface, or the spare copies of the data written to the first backup location or the second backup location contains errors;

setting the second backup location to a read-only status when the running number is an odd number and the data written to the disk surface or the spare copy of the data written to the first backup location contains errors; and

setting the first backup location to a read-only status when the running number is an even number and the data written to the disk surface or the spare copy of the data written to the second backup location contains errors.

14. The method of claim 13 further comprising:

replacing the data written to the disk surface with the spare copy of the data written to the first backup when the spare copy of the data written to the second backup location contains an error; and

replacing the data written to the disk surface with the spare copy of the data written to the second backup location when the spare copy of the data written to the first backup location contains an error.

15. The method of claim 9 wherein the disk surface further comprises a first working location and a second working location.

16. The method of claim 15 further comprising writing the data to the first working location when the running number is an odd number, and writing the data to the second working location when the running number is an even number.

17. The method of claim 16 further comprising:

determining whether the data written to the first working location or the second working location, or the spare copy of the data written to the first backup location or the second backup location contains errors;

setting the second working location and the second backup location to a read-only status when the running number is an odd number, and the data written to the first working location or the spare copy of the data written to the first backup location contains errors; and

setting the first working location and the first backup location to a read-only status when the running number is an even number, and the data written to the second working location or the spare copy of the data written to the second backup location contains errors.

Assignments (6)