Zoned Flash Storage Control for Random and Sequential Writes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing storage devices face challenges in improving operating speed and managing storage space efficiently, particularly in nonvolatile memory devices, which affect the performance of host devices.
Innovation Solution
The storage device employs a memory controller that manages storage space in zones, utilizing a zone map table and page map table to allocate logical addresses sequentially, and includes features like a shared or dedicated write booster buffer to enhance write speed, along with mechanisms for zone opening, closing, resetting, and garbage collection to optimize data management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sequential address mapping is used, then data management efficiency is improved, but write speed deteriorates due to frequent address translation operations
Solution Approach 1:
The patent pre-allocates contiguous physical address ranges for each logical address range in the zone map table before actual data writing occurs. This preliminary address mapping eliminates the need for real-time address translation during write operations, thus improving write speed while maintaining efficient data management through structured zone-based organization
2Quantity of substance
If zone-based management is implemented, then storage space utilization is improved, but device complexity increases due to multiple management tables
Solution Approach 1:
The patent divides the storage device into multiple zones with each zone having its own dedicated entry in the zone map table. This segmentation allows independent management of different storage regions, improving space utilization through targeted allocation while reducing overall complexity by localizing management operations to specific zones rather than managing the entire address space uniformly
3Speed
If buffer operations are added, then write speed is improved, but loss of time increases due to additional buffer management overhead
Solution Approach 1:
The patent introduces a buffer zone as an intermediary storage region between the host device and the main storage zones. This buffer absorbs write operations temporarily, allowing high-speed data ingestion without immediately propagating to all zones. The zone map table efficiently tracks buffer contents, minimizing overhead time while maintaining improved write speed through this intermediary layer
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A storage device, including: a nonvolatile memory device including a plurality of memory cells; and a controller configured to, based on receiving an open zone command from an external host device: based on a number of free erase units from among a plurality of erase units included in the plurality of memory cells being greater than a threshold value, allocate at least two free erase units to a first-type zone, and based on the number of the free erase units being smaller than or equal to the threshold value, allocate the at least two free erase units to a second-type zone. wherein the controller is further configured to permit a random write based on a random logical address received from the external host device for the first-type zone, and to permit a zone write based on a sequential logical address received from the external host device for the second-type zone.