Western Digital Technologies, Inc.

Heon Ho Chung

Chun Sei Tsai

Carl E Barlow

Kenneth J Smith

A method to enable defect margining of a disk drive may comprise executing a data access command on a target sector on the disk drive. Upon encountering a data access error at the target sector, an address of the target sector may be added to an error list. The address of the target sector in the error list may then be converted to a physical location on the disk drive. A thermal asperity scan may be performed at and around the physical location and, upon detecting a thermal asperity, and at least sectors around the detected thermal asperity may be margined, and the data stored within the margined sectors may be relocated. Instead of sectors, entire tracks may be margined and the data stored therein relocated to a spare or reserve location, one track at a time.

Methods and devices for preventing potential media errors from growing thermal asperities

A method of operating a disk drive comprises scanning each Logical Block Address (LBA) of the disk drive to detect a read error or reading the LBA from a media defect list. The LBA may then be converted to a corresponding physical location on the media and a scan of the corresponding physical location and of nearby physical locations that are within a proximity threshold of the corresponding physical locations may be performed to find media defects. Based thereon, it may then be determined whether a media scratch is present and at least one or more data sectors associated with the media scratch may be relocated to a spare location on the media if the media scratch is determined to be present. If the media scratch is determined not to be present, only the data sector associated with the corresponding physical location may be relocated to the spare location.

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Laguna Niguel, CA, United States of America

Heon Ho Chung