Nonvolatile Memory Metadata Recovery via Valid Page Tables
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Data storage devices with nonvolatile memory face challenges in efficiently rebuilding metadata during recovery from power failure states, as existing methods lack effective mechanisms for tracking valid and empty pages across memory blocks.
Innovation Solution
A data storage device and operating method that generate and backup valid page count and scan tables to efficiently manage metadata recovery, utilizing a nonvolatile memory device with closed, open, and meta blocks, and a controller to maintain and update these tables during power failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional metadata management methods are used in nonvolatile memory devices, then device simplicity is maintained, but metadata rebuilding efficiency during power failure recovery deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-generating and backing up valid page count tables and valid page scan tables before power failures occur. These tables are maintained in real-time during normal operation and stored in meta blocks, enabling rapid metadata recovery without complex rebuilding operations after power restoration
Solution Approach 2:
The patent introduces intermediary data structures (valid page count tables and valid page scan tables) that mediate between the physical memory blocks and the metadata management system. These intermediaries store critical information about valid page locations and counts, allowing efficient recovery without directly managing complex memory block states during power failure scenarios
2Reliability
If comprehensive tracking of valid pages across all memory blocks is implemented, then data integrity during recovery is improved, but the complexity of metadata management increases
Solution Approach 1:
The patent segments the metadata management into distinct components: valid page count tables that track the number of valid pages per block, and valid page scan tables that record locations of valid pages. This segmentation allows comprehensive tracking of data integrity while maintaining manageable complexity through modular table structures
Solution Approach 2:
The patent creates simplified copies of critical metadata information in the form of valid page count tables and scan tables stored in meta blocks. These copies contain essential recovery information without duplicating the entire memory block data structure, thereby ensuring data integrity while avoiding proportional increases in complexity
3Measurement precision
If real-time updates of valid page information are performed, then recovery accuracy is improved, but processing time and energy consumption increase
Solution Approach 1:
The patent applies partial action by updating only the specific portions of metadata that change during normal operation (valid page counts and scan pointers in the tables). Rather than reprocessing entire metadata structures, the system performs targeted updates to affected table entries, reducing processing time while maintaining accurate tracking
Solution Approach 2:
The metadata management system performs self-service by automatically maintaining valid page count tables and scan tables during normal write operations. The controller updates these tables in real-time without external intervention, ensuring accurate tracking of valid pages while minimizing processing overhead through integrated maintenance routines
Data Source
AI summary
A method for operating a data storage device which includes a nonvolatile memory device including a plurality of memory blocks, includes generating a valid page count table including the number of valid pages of each of closed blocks among the plurality of memory blocks in which data are written in all pages thereof and the number of valid pages of at least one open block among the plurality of memory blocks in which data is written in a part of pages thereof; generating a valid page scan table including a scan pointer for scanning the number of valid pages of the open block; and backing up the valid page count table and the valid page scan table in a meta block among the plurality of memory blocks.