Command History Buffer for Storage Failure Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional storage devices lack the ability to provide data on commands received by the NAND array, making it difficult to diagnose failures such as voltage drops, NAND timing violations, and noise on the NAND bus.
Innovation Solution
Implementing a command history buffer in the storage device to store information related to commands sent to the NAND array, allowing for better failure diagnosis and recovery by monitoring and correcting invalid command flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional storage devices are used without a command history buffer, then the device complexity is low, but the ability to diagnose failures and monitor NAND operations is insufficient
Solution Approach 1:
The command history buffer stores command sequences before failures occur, enabling post-event analysis. By preliminarily recording command flows, the system prepares diagnostic data in advance, allowing precise failure diagnosis without adding complex real-time monitoring hardware.
Solution Approach 2:
The command history buffer acts as an intermediary component between the controller and NAND array, capturing and preserving command sequences. This intermediary structure enables diagnostic capabilities by mediating the information flow without requiring direct complex monitoring between controller and memory.
2Reliability
If a command history buffer is implemented to store command sequences, then failure analysis capability is improved, but the device complexity increases
Solution Approach 1:
The command history buffer provides self-service by automatically capturing and storing command sequences without external intervention. This self-recording mechanism improves reliability for failure analysis while minimizing additional complexity, as the buffer operates autonomously to preserve diagnostic information.
Solution Approach 2:
The command history buffer creates a copy of the command sequence for diagnostic purposes while the original commands continue to execute. This copying approach enables failure analysis capability by preserving command information without interfering with normal operations, adding minimal complexity through a separate storage path.
3Measurement precision
If the command history buffer is used to monitor NAND operations, then measurement precision of command flows is improved, but loss of time for retrieving command information occurs
Solution Approach 1:
Command sequences are preliminarily stored in the history buffer during normal operations, so that when failures occur, the information is already captured and ready for immediate retrieval. This preliminary recording eliminates time loss during diagnostic investigations by having data prepared in advance.
4Loss of information
If conventional systems without command history buffering are used, then the device complexity is low, but information on NAND state during failures is unavailable
Solution Approach 1:
The command history buffer serves as an intermediary that captures and preserves command sequences, preventing information loss about NAND state during failures. This mediator structure ensures diagnostic information is retained without requiring complex real-time monitoring systems.
Data Source
AI summary
A data storage device for providing failure recovery may include a device memory including one or more memories and a command history buffer. The device memory may be configured to receive and process (i) commands directed to the one or more memories, and (ii) an access command for accessing the command history buffer. The command history buffer may be configured to store information related to the commands. The data storage device may also include a controller coupled to the device memory and configured to: send the commands to the device memory; retrieve information stored in the command history buffer from the device memory, by issuing the access command; and in accordance with a determination that the information stored in the command history buffer indicates invalid command flows, resend at least a portion of the commands to the device memory.