Detecting Shingled Overwrite Errors in Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Data storage devices face inefficiencies when encountering read errors on shingled recording tracks, as they often attempt ineffective error recovery operations due to misidentification of errors caused by shingled overwriting, leading to command timeouts and reduced performance.
Innovation Solution
A processor or controller module is configured to detect read errors and determine if they are caused by shingled overwriting, allowing for the cancellation of error recovery operations and preventing unnecessary resource expenditure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If error recovery operations are attempted for all read errors on shingled recording tracks, then data reliability may be improved, but device performance deteriorates due to command timeouts and unnecessary resource expenditure
Solution Approach 1:
The patent segments error handling into two distinct paths: shingled overwrite errors and non-shingled errors. By detecting whether a read error is caused by shingled overwriting, the system applies different recovery strategies - canceling recovery for shingled errors while attempting recovery for other errors, thus resolving the contradiction between reliability and performance
Solution Approach 2:
Instead of attempting error recovery for all read errors (conventional approach), the patent inverts the logic by canceling recovery operations specifically for shingled overwrite errors. This inversion recognizes that shingled errors are unrecoverable by traditional means, and attempting recovery only wastes resources and causes timeouts
2Productivity
If error recovery operations are canceled for shingled overwriting errors, then device performance is improved, but the ability to recover data from non-shingled errors may be reduced if misidentification occurs
Solution Approach 1:
The patent implements feedback by detecting read errors and determining their cause (shingled overwriting or other causes) before deciding on recovery operations. This feedback mechanism ensures that recovery is canceled only when appropriate (shingled errors) while maintaining recovery attempts for non-shingled errors, thus preserving data recovery capability while improving performance
Solution Approach 2:
The patent replaces the mechanical/universal error recovery mechanism with an intelligent detection system that identifies shingled overwrite errors through analysis of read error characteristics. This substitution allows differentiated handling of errors, replacing blind recovery attempts with targeted error classification and appropriate response
Data Source
AI summary
Systems and methods are disclosed for detecting shingled overwrite errors. When a read error is encountered when reading from shingled recording tracks, a processor may determine whether the read error is an error caused by shingled overwriting. The processor may determine whether the read error is caused by shingled overwriting by determining read signal quality of one or more sectors preceding the read error, such as based on a bit error count or bit error ratio (BER), and comparing the read signal quality to a threshold value. The processor may determine that the read error is caused by shingled overwriting when the read signal quality value is lower than the threshold.