Post-write scan operations for interlaced magnetic recording

• US 9,679,601 B2
• Filed: 04/01/2016
• Issued: 06/13/2017
• Est. Priority Date: 11/24/2014
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Gage, Edward, Gao, Kaizhong, Zhu, Wenzhong, Rausch, Tim
• Primary Examiner(s): Agustin, Peter Vincent
• Application Number:
  US15/089,239
• Publication Number:
  US 20160307595A1
• Time in Patent Office: 438 Days
• Field of Search: None
• CPC Class Codes: G11B 20/10212 compensation for data shift, e.g. pulse-crowding effects
• CPC Class Codes: G11B 20/1217 on discs
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 2020/10898 Overwriting or replacing recorded data
• CPC Class Codes: G11B 2020/1238 track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located
• CPC Class Codes: G11B 2020/1292 Enhancement of the total storage capacity
• CPC Class Codes: G11B 2020/1869 Preventing ageing phenomena from causing data loss, e.g. by monitoring the age of record carriers or by recognising wear, and by copying information elsewhere when a record carrier becomes unreliable
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence

Abstract

A storage device includes a data degradation management module that tracks a risk of data degradation by incrementing a track write counter of a first data track responsive to each data write command to a second data track, such as a data track directly adjacent to the first data track. If a count of the track write counter exceeds a count threshold, one or more post-write scan operations are performed to assess and/or repair data degradation of the first data track.

Claims

1. One or more tangible computer-readable storage media encoding computer-executable instructions for executing on a computer system a computer process, the computer process comprising:

incrementing a track write counter of a first data track responsive to a data write command to a second data track but not incrementing any track write counters responsive to a data write to the first data track.

2. The tangible computer-readable storage media of claim 1, wherein the computer process further comprises:

re-writing data of the first data track and data of at least one directly adjacent data track based on a count value of the track write counter.

3. The tangible computer-readable storage media of claim 1, wherein the computer process further comprises:

reading the first data track if a count of the track write counter satisfies a count threshold; and

re-writing data of the first data track if a number of read errors detected during the reading of the first data track satisfies an error threshold.

4. The tangible computer-readable storage media of claim 1, wherein the track write counter quantifies a risk of data degradation of the first data track.

5. The tangible computer-readable storage media of claim 1, wherein the first data track is directly adjacent to the second data track.

6. The tangible computer-readable storage media of claim 2, wherein re-writing the first data track and at least one directly adjacent data track further comprises:

re-writing data of data tracks directly adjacent to the first data track.

7. The tangible computer-readable storage media of claim 2, wherein the computer process further comprises:

resetting the track write counter of the first data track to a default value.

8. A method comprising:

incrementing a first track write counter responsive to a data write to a first data track but not incrementing any track write counters responsive to a data write to a second data track directly adjacent to the first data track.

9. The method of claim 8, wherein the method further comprises:

re-writing data of the first data track and data of the second data based on a count value of the first track write counter.

10. The method of claim 8, wherein the method further comprises:

reading the first data track if a count of the track write counter satisfies a count threshold; and

re-writing data of the first data track if a number of read errors detected during the reading of the first data track satisfies an error threshold.

11. The method of claim 9, further comprising:

resetting the track write counter of the first data track to a default value.

12. The method of claim 9, further comprising:

incrementing a track write counter of a third data track and a track write counter for a fourth data track responsive to the re-write of data of the first data track, the second data track and the third data track each separated from the first data track by one interlaced data track.

13. A storage system comprising:

a degradation management module configured to increment a track write counter of a first data track responsive to a data write command to a second data track but not increment any track write counters responsive to a data write to a second data track directly adjacent to the first data track.

14. The storage system of claim 13, further comprising:

a read/write management module coupled to a memory and configured to re-write data of the first data track and data of at least one data track directly adjacent to the first data track based on the value of the write track counter.

15. The storage system of claim 13, wherein the first data track is directly adjacent to the second data track.

16. The storage system of claim 14, wherein the degradation management module is further configured to reset the track write counter to a default value responsive to the re-write of data of the first data track.

17. The storage system of claim 14, wherein the degradation management module is further configured to increase the track write counter of the first data track responsive to the re-write of the data of the at least one adjacent data track.

18. The storage system of claim 14, wherein the degradation management module is further configured to increment a track write counter of a third data track and a track write counter for a fourth data track responsive to the re-write of the data of first data track, the third data track and the fourth data track each separated from the first data track by one interlaced data track.

19. The storage system of claim 14, wherein the read/write management module re-writes data of the first data track before writing data of the at least one data track directly adjacent to the first data track.