Concurrent RRA and IOC Decoding for Faster Disk Read Recovery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The sequential execution of recursive read averaging (RRA) and iterative outer code (IOC) recovery processes in disk drives leads to higher command completion times, which is a critical issue for cloud storage customers requiring rapid data recovery.

Innovation Solution

Implementing a concurrent error recovery system with co-dependent circuit blocks that perform multiple rounds of RRA and IOC recovery processes, allowing bidirectional feedback and interleaved operations to enhance decoding efficiency and reduce latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If sequential recovery algorithms are used, then implementation simplicity is maintained, but command completion time increases

Engineering Contradiction:

Improveimplementation simplicityVSAvoidcommand completion time

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The recovery system is segmented into multiple independent circuit blocks, each dedicated to a specific recovery algorithm (RRA, IOC, or both concurrent). This segmentation allows parallel execution of multiple recovery algorithms simultaneously, reducing command completion time while maintaining implementation simplicity through modular architecture

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from sequential (one-dimensional) execution of recovery algorithms to concurrent parallel execution (adding a temporal dimension). Multiple recovery algorithms operate simultaneously in different circuit blocks rather than one after another, fundamentally changing the execution paradigm to reduce latency

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of time

If powerful recovery algorithms are invoked early, then command completion time is reduced, but computational complexity increases

Engineering Contradiction:

Improvecommand completion timeVSAvoidcomputational complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

Complex recovery operations are divided into separate circuit blocks, each handling specific algorithms. This segmentation allows powerful algorithms to be invoked early without overwhelming a single processor, distributing computational complexity across multiple specialized units

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Sample data acts as an intermediary between the RRA and IOC circuit blocks. Each block processes samples independently and feeds results back to the other, allowing complex computations to be broken into manageable steps with intermediate results shared between blocks

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11336304B2Concurrent recursive-read averaging and iterative inner and outer code decoding

Publication Date: 2022.05.17 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

In one implementation, the disclosure provides a decoding system that concurrently executes a read sample combining recovery process and an iterative outer code (IOC) recovery process. Performing the read sample combining recovery process entails executing multiple rounds of logic that each provide for combining together different data samples read from a data block. The IOC recovery process is performed at least partially concurrent with the read sample combining recovery process and each round of the IOC recovery process is based on newly-updated data samples generated by the read sample combining recovery process.