NVM Drive Storage System Eliminating Spare Areas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile memory (NVM) drives, such as SSDs with NAND-type flash memory, face limitations in data storage capacity due to the need for spare areas for reclamation processes, leading to lower bit costs and inefficient data management, as valid and invalid data are often mixed within physical blocks, necessitating additional write areas and erasure processes.
Innovation Solution
Implementing a storage system where the entire physical area of the NVM drive is utilized as a user area, eliminating spare capacity and allowing for continuous logical address ranges, with data relocation between chunks managed to avoid mixing valid and invalid data, thereby eliminating the need for reclamation processes and optimizing bit costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spare area is allocated for reclamation process, then data management reliability is improved, but storage capacity is reduced
Solution Approach 1:
The invention extracts the reclamation function from the traditional spare area concept and implements it through a different mechanism. Instead of dedicating physical spare blocks for reclamation, the system uses a mapping table structure that enables logical reclamation without consuming additional physical capacity, thereby resolving the contradiction between reliability and storage capacity.
Solution Approach 2:
The invention introduces a mapping table as an intermediary between the host and physical storage blocks. This mapping table enables the system to track valid and invalid data locations, facilitating reclamation operations without requiring dedicated spare physical blocks, thus maintaining both reliability and maximizing storage capacity.
2Productivity
If reclamation process is implemented, then storage efficiency is improved, but device complexity increases
Solution Approach 1:
The invention implements self-service reclamation where the system automatically manages data relocation and block reclamation without requiring complex external intervention. The mapping table structure enables automatic tracking and management of valid/invalid data, reducing the complexity of reclamation operations while maintaining high storage efficiency.
Solution Approach 2:
The invention changes the parameter of reclamation from a complex physical data movement process to a simpler logical mapping update process. By using the mapping table to track block validity, the system achieves efficient reclamation through parameter changes in the mapping structure rather than complex physical operations.
3Adaptability or versatility
If physical blocks contain mixed valid and invalid data, then storage flexibility is improved, but bit cost decreases
Solution Approach 1:
The invention segments the storage management into logical units using the mapping table structure. Each mapping entry tracks the validity of specific physical blocks, enabling the system to manage mixed valid/invalid data at the block level while maintaining overall storage flexibility. This segmentation allows efficient identification and reclamation of invalid blocks without affecting valid data.
Solution Approach 2:
The invention applies local quality management by treating each physical block's validity status independently through the mapping table. The system can identify and reclaim invalid blocks locally without affecting other blocks, maintaining storage flexibility while optimizing bit cost through targeted reclamation operations.
Data Source
AI summary
A higher-level system that inputs and outputs data to/from a storage area including one or more logical areas respectively provided from one or more NVM drives manages the storage area, and manages a plurality of chunks that are a plurality of areas forming the storage area, each of the chunks being a unit of data input/output and being an non-overwritable area. Each of the plurality of chunks has the same chunk size, and each of the plurality of chunks includes a part of each of one or more logical areas. Each of the plurality of chunks includes, for each of the one or more NVM drives, all or part of one or more logical blocks that are one or more ranges corresponding to one or more physical blocks, respectively, but does not include at least a part of a logical block that is entirely or partially included in another chunk.