Magnetic Disk Track Protection via Adaptive ATI Counter Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic disk devices face challenges in maintaining effective track protection against adjacent track interference (ATI), leading to difficulties in reading data due to increased interference over time, which existing methods address inadequately by requiring frequent rewrite operations and recalculating parity, thereby increasing processing time and reducing write performance.
Innovation Solution
The magnetic disk device incorporates a controller that manages ATI counters to identify tracks needing rewrite, merges write data with existing track data, updates and recalculates parity during the write operation, and resets ATI counters, thereby reducing the number of write operations and maintaining track protection functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequent rewrite operations are performed to maintain track protection against ATI, then data readability is maintained, but write performance deteriorates and processing time increases
Solution Approach 1:
The patent applies preliminary action by incrementing ATI counters during normal write operations to tracks adjacent to the write destination track, before actual ATI interference occurs. This allows the system to proactively identify tracks that will need rewriting due to anticipated interference, enabling scheduled rewriting at optimal times rather than reactive rewriting when read errors occur, thus maintaining data readability while reducing urgent rewrite operations that degrade write performance
2Reliability
If track protection is maintained through frequent parity recalculation and rewrite operations, then data integrity against ATI is preserved, but processing time increases
Solution Approach 1:
The patent implements feedback by continuously monitoring ATI counter values for tracks adjacent to write destination tracks and using this information to determine when rewriting is necessary. The controller increments ATI counters based on write operations and compares them against thresholds to trigger selective rewriting and parity recalculation only when needed, rather than performing these operations frequently or continuously. This feedback mechanism maintains track protection effectiveness while minimizing unnecessary processing time consumption
3Productivity
If selective rewrite operations are performed based on ATI counter thresholds, then the number of write operations is reduced, but complexity of track management increases
Solution Approach 1:
The patent applies segmentation by dividing track management into distinct components: individual ATI counters for each track, separate threshold levels for triggering rewrite operations, and independent parity management for each track. This modular approach allows the controller to manage each track independently based on its specific ATI risk level, reducing write operations through selective rewriting while keeping track management complexity manageable through structured, incremental counter updates and clear threshold-based decision rules
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves write performance by minimizing the number of write operations and ensuring the track protection function remains effective, reducing processing time and preventing data read difficulties due to ATI, while avoiding the need for post-write parity recalculation.
Implementation Method 1
The magnetic head writes and reads data to and from a magnetic disk
Implementation Method 2
a magnetic disk provided with a first track including a plurality of first sectors and a second sector
Data Source
AI summary
According to an embodiment, a track includes first sectors and a second sector. When write of a second data segment to a third sector that is one of the first sectors is requested from a host, a controller acquires the second data segment from the host and stores the second data segment in the memory, and reads a data set including all first data segments and all first information pieces from the track and stores the data set in the memory. The controller acquires a second information piece of the third sector, and updates a first data segment and a first information piece read from the third sector in the data set in the memory with the second data segment and the second information piece. The controller calculates a second parity while the updated data set to the track, and writes the second parity to the second sector.