Apparatus and method for dynamically performing knowledge-based error recovery

A system for dynamically performing knowledge-based error recovery in a tape drive data storage device having one or more read/write heads, comprising:

• means for generating a data structure comprising plural storage array locations corresponding to locations on said tape medium;
• means for sequentially storing in said data structure storage array locations, a continuous series of values representing error information determined from data transfer operations performed by the tape drive data storage device;
• means for determining whether an error recovery event has occurred;
• and
• means responsive to said error recovery determining means for performing one or more selected error recovery actions upon said values stored in said data structure exceeding one or more threshold values.

In a tape drive data storage apparatus including a control system for reading and writing host data on a streaming tape medium, an error correction coding (ECC) system for detecting and correcting data transfer errors, and an error recovery system for performing non-ECC correctable error recovery, a method for dynamically performing knowledge-based error recovery comprising the steps of:

• performing read and/or write data transfer operations on multiple tracks of a tape medium loaded in the tape drive;
• generating during said data transfer operations an error recovery knowledge base representing a tape map of ECC error correction locations on said tape medium, said tape map defining a hierarchy of tape tachometer regions, tape wraps, tape wrap halfs and tape tracks;
• determining from said tape map upon initiation of an error recovery event whether one or more error clustering thresholds have been reached in one or more selected regions of the tape;
• and if so
• modifying the error recovery performed by the error recovery system in said selected tape regions;
• said clustering thresholds including a vertical clustering threshold representing said ECC error correction locations occurring in a selected number of said tape tracks in one or more of said tape tachometer regions;
• said clustering thresholds further including a horizontal clustering threshold representing said ECC error locations occurring in one or more said tape tracks in a selected number of said tape tachometer regions;
• and
• said cyclical defect threshold representing one or more ECC error correction locations occurring at selected distances from each other along said tape medium corresponding to the diameter of a hub around which said tape medium is wound.