Variable Capacity Zone Namespace Flash Storage Data Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Zone Namespace (ZNS) flash storage, when a host explicitly closes not fully written zones, additional actions are necessary to ensure host data readability, leading to overhead and reduced performance due to the need for padding in final flash blocks.
Innovation Solution
A variable capacity scheme is implemented using a folding algorithm to compact host data from multiple zones into a final flash block, delaying the association of the final flash block and staging data for efficient storage, thereby reducing the need for additional writes and padding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional actions are taken to ensure host data readability when explicitly closing not fully written zones, then data integrity is maintained, but overhead increases and performance decreases
Solution Approach 1:
The patent applies preliminary action by pre-associating multiple zones with a single final flash block before all zones are fully written. This allows the system to prepare the storage structure in advance, so when zones are closed early, no additional padding or reallocation actions are needed, thus maintaining data readability while avoiding performance overhead.
Solution Approach 2:
The patent merges multiple zones into a single shared final flash block. Instead of dedicating separate flash blocks to each zone, multiple zones share the same final block, which eliminates the need for individual padding operations when zones are closed early, thereby reducing overhead while ensuring data integrity.
2Reliability
If padding is added to final flash blocks to ensure data readability, then data integrity is maintained, but storage efficiency decreases
Solution Approach 1:
Multiple zones share a common final flash block, allowing the system to consolidate data from different zones into the same physical block without requiring padding for each individual zone. This merging approach maximizes storage efficiency while maintaining data readability.
Solution Approach 2:
The patent implements dynamic zone-to-block association where the final flash block assignment is flexible and adapts based on actual write patterns. Zones can be dynamically associated with the shared final block only when needed, avoiding static padding allocations and improving storage efficiency.
3Ease of operation
If separate flash blocks are associated with each zone, then data management is simplified, but storage capacity utilization decreases
Solution Approach 1:
The patent merges multiple zones into shared final flash blocks, increasing storage capacity utilization by allowing multiple zones to occupy the same physical storage space. Data management remains simplified through the use of a zone information table that tracks zone-to-block associations.
Solution Approach 2:
The patent introduces a zone information table as an intermediary data structure that manages the mapping between zones and shared final flash blocks. This intermediary layer simplifies data management by providing a centralized lookup mechanism while enabling efficient storage capacity utilization through shared blocks.
Data Source
AI summary
Variable Capacity Zone Namespace (ZNS) Flash Storage Data Path. In one example, a data storage device including an electronic processor that, when executing a variable capacity scheme, is configured to determine whether a special indication regarding a particular zone in a ZNS is received, delay an association of a final flash block with the particular zone, receive and stage host data for the particular zone in a staging area, receive a zone close request, compact the host data with other host data for storage in other zones into second host data, and move the second host data to the final flash block that is associated with the particular zone and the other zones. The compaction of the host data with the other host data into the second host data reduces or eliminates padding in the final flash block, and consequently, reduces overhead in the data storage device.