Storage Controller Sequential Write Order Guarantee
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing storage devices with non-volatile memory, such as flash memory, face challenges in maintaining write reliability and performance, particularly in ensuring the sequential order of writing data without degrading performance or requiring additional commands like flush or barrier commands.
Innovation Solution
A storage device with a controller that includes a command classification module to determine sequential data and a mapping manager to update logical-physical address mapping data based on the order of received write commands, ensuring the permanence and order of sequential data writing without the need for additional commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the storage device uses traditional write methods without sequential data detection, then the write operation is simple and fast, but the write reliability and data permanence order cannot be guaranteed
Solution Approach 1:
The controller performs preliminary detection of sequential data characteristics in write commands before executing the write operation. By detecting whether write data is sequential data requiring order guarantee, the controller can proactively apply appropriate write strategies (sequential write with order guarantee or normal write) to ensure data reliability while maintaining operational simplicity
Solution Approach 2:
The write operation is segmented into different processing paths based on data characteristics. The controller divides write operations into sequential data writes (requiring order guarantee) and non-sequential data writes (normal processing). This segmentation allows the system to apply complexity only where necessary, improving reliability for sequential data while maintaining simplicity for other cases
2Reliability
If the storage device guarantees sequential write order for all data, then the data permanence order is ensured, but the write performance degrades due to additional flush or barrier commands
Solution Approach 1:
The storage device applies different write quality levels to different data types. Sequential data receives enhanced treatment with order guarantee mechanisms, while non-sequential data uses standard write operations. This localized quality approach ensures data permanence order where needed without applying performance-degrading measures universally
Solution Approach 2:
The controller changes the write operation parameters dynamically based on detected data characteristics. When sequential data is detected, the system adjusts write parameters to guarantee order (updating mapping data sequentially). When non-sequential data is detected, normal write parameters are used. This parameter adaptation maintains high performance while ensuring reliability when required
3Reliability
If the storage device updates mapping data sequentially for all write commands, then the write order is guaranteed, but the processing time increases and performance decreases
Solution Approach 1:
The controller applies sequential mapping data update (excessive action for reliability) only to sequential data writes, while using partial action (normal update) for non-sequential data. This selective application of the more time-consuming update method reduces overall processing time while maintaining write order guarantee where it is actually needed
Data Source
AI summary
A method of operating a storage device including a non-volatile memory includes: the storage device receiving from a host a first write command; determining, based on the first write command, whether first write data for the first write command is sequential data required to be written according to a write request order; writing the first write data in the non-volatile memory; and when the first write data and second write data for a second write command are sequential data, sequentially updating first mapping data including a mapping relationship between a first logical address and a first physical address for the first write data, and updating second mapping data including a mapping relationship between a second logical address and a second physical address for the second write data, according to an order in which the first write command and the second write command are received.