Host I/O Filter Redirecting SSD Reads to RAM

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Solution Overview

Problem

Frequent read operations in solid-state drives (SSDs) can cause electrical resonance errors in adjacent cells, leading to data loss due to undetected errors in adjacent blocks, as the controller infrequently scans the entire media for error counts.

Innovation Solution

An I/O filter system within the host's operating system monitors read operations and redirects successive reads of frequently accessed data to a RAM buffer, mitigating errors by reducing the load on the SSD controller and allowing for error correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If read operations are frequently performed on SSD memory blocks, then data access speed is improved, but electrical resonance errors occur in adjacent cells leading to data loss

Engineering Contradiction:
Improvedata access speedVSAvoiddata integrity
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent introduces an I/O filter as an intermediary component between the host and SSD controller. This filter monitors read operations, identifies frequently accessed blocks, and redirects subsequent reads to a cache memory, thereby reducing the frequency of reads to the SSD and preventing electrical resonance errors in adjacent cells while maintaining fast data access through the cache path

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary actions by proactively identifying blocks that are likely to be frequently accessed and pre-caching their contents in memory before actual read operations occur. The I/O filter monitors access patterns and prepares cache entries in advance, so when read operations occur, the data can be served from cache without repeatedly accessing the SSD, thus preventing resonance errors before they accumulate

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the SSD controller frequently scans the entire media for error correction, then data reliability is improved, but system productivity deteriorates

Engineering Contradiction:
Improveerror correction capabilityVSAvoidsystem throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Instead of uniformly scanning the entire SSD media, the system applies local quality by focusing error correction resources only on specific blocks that are identified as frequently accessed or potentially problematic. The I/O filter directs attention to particular blocks that need monitoring, allowing the controller to perform targeted error checks rather than exhaustive full-media scans, thus maintaining reliability while improving productivity

Inventive Principle:
Principle #3Local quality

3Reliability

If an I/O filter redirects read operations to a cache, then the frequency of read operations on SSD blocks is reduced, but device complexity increases

Engineering Contradiction:
Improveprevention of electrical resonance errorsVSAvoidsystem architecture complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The I/O filter is designed with multi-functionality, serving as a monitoring component, a redirection component, and a cache management component all in one. By consolidating these functions into a single filter module, the patent reduces the need for separate complex components while achieving the goal of reducing read operation frequency to prevent electrical resonance errors

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3504627B1Read operation redirect
Publication Date: 2021.06.30 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3504627B1 patent drawingFigure 1
  • EP3504627B1 patent drawingFigure 2
  • EP3504627B1 patent drawingFigure 3

AI summary

Example implementations relate to read operation redirect. For example, a system according in the present disclosure may include a data storage device accessible by a host. The system may include an input/output filter of an operating system of the host. The input/output filter may monitor read operations and write operations from the host to the data storage device. The input/output filter may copy a portion of the data storage device to a random-access memory (RAM) buffer within the host responsive to monitored read operations to the portion exceeding a threshold. The input/output filter may redirect a successive read operation, addressed to the portion of the data storage device, to the copy of the portion in the RAM buffer.