Preventive recovery from adjacent track interference

• US 20070074083A1
• Filed: 09/20/2005
• Published: 03/29/2007
• Est. Priority Date: 09/20/2005
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Haines, Jonathan, Feldman, Timothy, Emo, Bruce, Coonen, Dan, Touchton, James, Olds, Edwin
• Granted Patent: US 7,747,907 B2
• Time in Patent Office: Days
• US Class Current: 714/54
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G06F 11/008 Reliability or availability analysis
• CPC Class Codes: G11B 20/1883 Methods for assignment of alternate areas for defective areas
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers

Abstract

A predictive failure control circuit and associated method are provided in a data storing and retrieving apparatus. The circuit is configured to schedule a data integrity operation on data associated with a subportion of a data storage space, in relation to a comparison of an accumulated plurality of executed host access commands associated with the subportion. The subportion can comprise a sector or a single track or a band of tracks. A table preferably stores accumulated number of host access commands for each of a plurality of subportions of the data storage space. The data integrity operation can comprise reading the data on to detect degradation and restoring the recovered data to the same or to new, different tracks. The data subportions can also be reallocated to a new location.

Claims

1. A predictive failure control circuit apparatus configured to schedule a data integrity operation on data associated with a subportion of a data storage space in relation to an accumulated plurality of executed host access commands associated with the subportion in comparison to a threshold accumulation.

2. The apparatus of claim 1 comprising a count table stored in memory configured to store values indicating a cumulative number of host access commands for each of a plurality of different storage subportions in the storage space.

3. The apparatus of claim 2 comprising a filtering table stored in memory configured to store a queue of values indicating the cumulative number of host access commands for each of a plurality of different storage subportions that are not in the count table but that are candidates for populating the count table in relation to subsequent host access commands.

4. The apparatus of claim 1, wherein the subportion is defined as a data storage track, and wherein the data integrity operation is performed on a first data storage track in response to the count table value of a second data storage track.

5. The apparatus of claim 4 wherein the first and second data storage tracks are adjacent.

6. The apparatus of claim 5 wherein the first and second tracks overlap.

7. The apparatus of claim 1 wherein the subportion is defined as a plurality of adjacent data storage tracks.

8. The apparatus of claim 7 wherein the plurality of data storage tracks are overlapping.

9. The apparatus of claim 7 wherein the count table value accumulates host access commands to any of the plurality of data storage tracks.

10. The apparatus of claim 9 wherein the count table value accumulates weighted incremental data associated with respective locations of the host access commands within the plurality of data storage tracks.

11. The apparatus of claim 1 wherein the host access commands are characterized by storing input data to the storage space.

12. The apparatus of claim 11 wherein the data integrity operation is characterized by non-host commands to scan the storage space in order to retrieve output data.

13. The apparatus of claim 12 wherein the data integrity operation is characterized by reducing an effectiveness of an error correction scheme while scanning the storage space.

14. The apparatus of claim 12 further configured to compare the cumulative number of host access commands to the threshold for scheduling a recommended data integrity operation and to compare the cumulative number of host access commands to a second threshold for implementing a mandatory data integrity operation.

15. A method comprising:

defining a subportion of a data storage space; and

scheduling a data integrity operation on data associated with the subportion in relation to an accumulated plurality of executed host access commands associated with the subportion.

16. The method of claim 15 comprising storing a respective cumulative number of host access commands for each of a plurality of different subportions.

17. The method of claim 16 wherein the scheduling step is characterized by scanning a first data storage track to retrieve output data in response to accumulating a predetermined number of host access commands storing input data to a second data storage track different than the first data storage track.

18. The method of claim 17 wherein the defining step is characterized by assigning a plurality of data storage tracks comprising the first and second data storage tracks to one subportion.

19. The method of claim 17 wherein the scheduling step is characterized by scheduling a recommended data integrity operation in relation to a first threshold and by implementing a mandatory data integrity operation in relation to a second threshold.

20. An apparatus comprising:

a data transfer member responsive to host commands in a data storing and retrieving relationship with a storage medium; and

means for preventing adjacent track interference on the storage medium in relation to an accumulated plurality of executed host access commands associated with a selected subportion of the medium.