Disk Drive Track Defect Map for Buffer Memory Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In disk drive data storage systems, especially in small form-factor devices, the limited buffer memory capacity is compromised by the need to store large global defect tables, leading to performance degradation due to the allocation of significant space for defect information, which is not efficiently managed in existing zone-based systems.
Innovation Solution
Implementing a track defect list stored on each disk track, reducing the need for a global defect list in buffer memory, and using a track defect field to store defect information locally, allowing only the necessary track defect list to be copied into the buffer memory during access, thereby freeing up space for user data buffering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a global defect list is stored in buffer memory to manage disk defects, then defect management capability is improved, but buffer memory capacity is reduced leading to performance degradation
Solution Approach 1:
The patent divides the global defect list into multiple zone defect lists, each managing defects for a specific zone of the disk. This segmentation reduces the amount of defect information that needs to be stored in buffer memory at any one time, while maintaining comprehensive defect management capability across the entire disk surface.
Solution Approach 2:
The patent implements zone-based defect management where each zone has its own defect list stored in buffer memory. This local approach allows the system to load only the defect information relevant to the currently accessed zone, rather than loading the entire global defect list, thereby optimizing buffer memory utilization and improving data transfer performance.
2Quantity of substance
If zone-based defect tables are used to reduce buffer memory usage, then buffer capacity is improved, but device complexity increases
Solution Approach 1:
The patent creates a zone defect list template that can be replicated for multiple zones. This template-based approach provides a universal structure that simplifies the management of multiple zone-specific defect lists, reducing the overall system complexity compared to implementing entirely separate defect management systems for each zone.
Solution Approach 2:
The patent pre-organizes defect information into zone-specific lists during disk initialization and manufacturing. This preliminary organization of defect data into manageable zones before actual disk operations begin simplifies subsequent defect management operations, as the system only needs to retrieve and process relevant zone data during normal operation rather than managing a monolithic global defect list.
Data Source
AI summary
A method and apparatus for storing a disk drive media defect table or list. Defect table entries for a subject disk track are stored on the subject track and retrieved for determining defective sectors only when the subject track is accessed for a data read or write operation.