Identifying a defect in a data-storage medium

1. A data read path, comprising:

a defect detector configured to identify a defective region of a data-storage medium by at least

determining a level of channel-detector values generated in response to the defective region, and

identifying the defective region in response to the level, the identifying comprising:

determining a respective correlation level for each of multiple overlapping windows of state-metric values, each window having a same size and corresponding to a respective data-storage location of the data-storage medium; and

identifying the defective region as including a first region of the data-storage medium where the correlation levels of the windows corresponding to the data-storage locations within the first region have a relationship to a first threshold; and

a data recovery circuit configured to recover data from the data-storage medium in response to the defect detector.

2. The data read path of claim 1 wherein the defect detector is further configured to identify the defective region by at least:

determining respective correlation levels of the channel-detector values respectively generated in response to multiple regions of the data-storage medium, the multiple regions including the defective region; and

identifying the defective region as including a first region where a correlation level corresponding to the first region has a relationship to a second threshold.

3. The data read path of claim 1 wherein

identifying the defective region further comprises identifying the defective region as including at least one second region adjacent to the first region.

4. The data read path of claim 1 wherein the data-storage medium comprises a disk drive.

5. A media drive comprising:

a data-storage medium configured to store data;

a media-drive controller comprising a data-write path configured to write data to the data-storage medium; and

a data read path comprising

a defect detector configured to identify a defective region of a data-storage medium by at least determining a level of channel-detector values generated in response to the defective region and identifying the defective region in response to the level, the identifying comprising:

determining a respective correlation level for each of multiple overlapping windows of state-metric values, the state-metric values being different from the channel-detector values, each window having an identical length and corresponding to a respective data-storage location of the data-storage medium; and

identifying the defective region as including a first region of the data-storage medium where the correlation levels of the windows corresponding to the data-storage locations within the first region have a relationship to a first threshold, and

a data recovery circuit configure to recover data from the data-storage medium in response to the defect detector.

6. The media drive of claim 5 wherein the defect detector is further configured to identify the defective region by at least:

determining respective correlation levels of the channel-detector values respectively generated in response to multiple regions of the data-storage medium, the multiple regions including the defective region; and

identifying the defective region as including a first region where a correlation level corresponding to the first region has a relationship to a second threshold.

7. The media drive of claim 5 wherein

identifying the defective region further comprises identifying the defective region as including at least one second region adjacent to the first region.

8. The media drive of claim 5 wherein the data-storage medium comprises a disk drive.

9. A method comprising:

identifying a defective region of a data-storage medium by at least determining a level of channel-detector values generated in response to the defective region, and identifying the defective region in response to the level, the identifying further comprising:

determining a respective correlation level for each of multiple overlapping windows of state-metric values, each window including an identical number of samples and corresponding to a respective data-storage location of the data-storage medium; and

identifying the defective region as including a first region of the data-storage medium where the correlation levels of the windows corresponding to the data-storage locations within the first region have a relationship to a first threshold; and

recovering data from the data-storage medium in response to the defect detector.

10. The method of claim 9 wherein identifying the defective region further comprises:

determining respective correlation levels of the channel-detector values respectively generated in response to multiple regions of the data-storage medium, the multiple regions including the defective region; and

identifying the defective region as including a first region where a correlation level corresponding to the first region has a relationship to a second threshold.

11. The method of claim 9 wherein identifying the defective region further comprises:

identifying the defective region as including at least one second region adjacent to the first region.

12. The method of claim 9 wherein the data-storage medium comprises a disk drive.

13. A method comprising:

identifying a defective region of a data-storage medium, the identifying comprising:

determining a respective correlation level for each of multiple overlapping windows of state-metric values, each window having a same length and corresponding to a respective data-storage location of the data-storage medium; and

identifying the defective region as including a first region of the data-storage medium where the correlation levels of the windows corresponding to the data-storage locations within the first region have a relationship to a first threshold;

recovering a first data element from the identified defective region;

recovering a second data element from another region of the data-storage medium that is not identified as being defective;

generating a first reliability value corresponding to the first data element in a first manner; and

generating second reliability value corresponding to the second data element in a second manner that is different from the first manner.

14. The method of claim 13 wherein identifying the defective region comprises:

determining a level of channel-detector values generated in response to the defective region; and

identifying the defective region in response to the level.

15. The method of claim 14 wherein identifying the defective region further comprises:

determining respective correlation levels of the channel-detector values respectively generated in response to multiple regions of the data-storage medium, the multiple regions including the defective region; and

identifying the defective region as including a first region where a correlation level corresponding to the first region has a relationship to a second threshold.

16. The method of claim 14 wherein identifying the defective region further comprises:

identifying the defective region as including at least one second region adjacent to the first region.

17. The method of claim 13 wherein the data-storage medium comprises a disk drive.