Micro-journaling of data on a storage device

• US 20070097535A1
• Filed: 11/03/2005
• Published: 05/03/2007
• Est. Priority Date: 11/03/2005
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: New, Richard, Colegrove, Daniel
• Granted Patent: US 7,986,480 B2
• Time in Patent Office: Days
• US Class Current: 360/31
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 2220/2516 Hard disks
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06

Abstract

Embodiments of the present invention recite a method of preserving data on a hard disk drive. In one embodiment, a first copy of data is read from at least one sector of a hard disk drive and stored in a first location. A second copy of the data is stored in a non-volatile memory location of the hard disk drive. The first copy of the data is then modified to create a modified copy. The second copy of the data is then used to verify that the modified copy of data has been correctly written to the at least one sector of the hard disk drive.

Claims

1. A method for preserving data on a hard disk drive, said method comprising:

storing a copy of data read from at least one sector of a hard disk in a non-volatile memory location of said hard disk drive; and

using said copy of data to verify that a modified copy of data has been correctly written to said at least one sector.

2. The method as recited in claim 1 further comprising:

determining that said modified copy of data has not been correctly written to said at least one sector; and

restoring said copy of data in said at least one sector.

3. The method as recited in claim 1 wherein using said copy of data to verify that said modified copy has been correctly written to said at least one sector further comprises;

determining that said copy of data comprises a valid copy of data.

4. The method as recited in claim 1 wherein storing said copy of data further comprises:

storing said copy of data in non-volatile memory location of said hard disk drive that is separate from said hard disk.

5. The method as recited in claim 1 wherein said method further comprises:

reserving a plurality of locations of said hard disk for storing said copy of data.

6. The method as recited in claim 1 wherein said method further comprises:

storing an indication of the location of said at least one sector with said copy of data.

7. The method as recited in claim 1 further comprising:

receiving a command to perform an unaligned write operation to said at least one sector; and

reading said copy of data from said hard disk.

8. A system for preserving data on a hard disk drive, said system comprising comprising:

a housing;

a disk pack mounted to said housing and comprising at least one hard disk that is rotatable relative to said housing, the disk pack defining an axis of rotation and a radial direction relative to the axis;

a non-volatile memory mounted to said housing which is separate from said at least one hard disk; and

a controller mounted to said housing, said controller comprising a non-volatile memory which is separate from said at least one hard disk, said controller further for implementing a method for preserving data on a hard disk drive, said method comprising;

storing a copy of data read from at least one sector of a hard disk in a non-volatile memory location of said hard disk drive; and

using said copy of data to verify that a modified copy of data has been correctly written to said at least one sector.

9. The system of claim 8 wherein said method further comprises:

determining that said modified copy of data has not been correctly written to said at least one sector; and

restoring said copy of data in said at least one sector.

10. The system of claim 8 wherein using said copy of data to verify that said modified copy has been correctly written to said at least one sector further comprises;

determining that said copy of data comprises a valid copy of data.

11. The system of claim 8 wherein storing said copy of data further comprises:

storing said copy of data in non-volatile memory location of said hard disk drive that is separate from said hard disk.

12. The system of claim 8 wherein said method further comprises:

reserving a plurality of locations of said hard disk for storing said copy of data.

13. The system of claim 8 wherein said method further comprises:

storing an indication of the location of said at least one sector with said copy of data.

14. The system of claim 8 wherein said method further comprises:

receiving a command to perform an unaligned write operation to said at least one sector; and

reading said copy of data from said hard disk.

15. A hard disk drive system comprising:

a disk pack comprising at least one hard disk;

a storage means for storing a copy of data read from at least one sector of said disk pack; and

a controlling means for using said copy of data to verify that a modified copy of said copy of data has been correctly written to said at least one sector.

16. The hard disk drive system of claim 15 wherein said controlling means is further for restoring said copy of data to said at least one sector in response to determining that said modified copy of said data has not been correctly written to said at least one sector.

17. The hard disk drive system of claim 15 wherein said storage means is in a separate location of said hard disk drive system from said at least one hard disk.

18. The hard disk drive system of claim 15 wherein said controlling means is further for indicating that said copy of said data comprises an invalid copy of data when said modified copy has been correctly written to said at least one sector.

19. The hard disk drive system of claim 15 wherein said storage means is further for storing an indication of the location of said at least one sector with said copy of data.