Volatile-Memory Redundancy for Non-Volatile Storage Recovery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing non-volatile memory systems face challenges in maintaining storage reliability and efficiency due to the limitations of storing redundancy information in non-volatile memory, which can lead to increased latency and reduced memory lifetime.

Innovation Solution

Storing redundancy information in volatile memory, such as RAM, allows for faster data retrieval and management, reducing overall data storage latency and increasing memory lifetime by utilizing volatile memory's higher programming cycles and simpler management tasks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If redundancy information is stored in non-volatile memory, then storage reliability is improved, but data retrieval speed deteriorates and latency increases

Engineering Contradiction:

Improvestorage reliabilityVSAvoiddata retrieval speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent divides the storage system into two distinct memory types: non-volatile memory for storing data items and volatile memory for storing redundancy information. This segmentation allows each memory type to be optimized for its specific function, with non-volatile memory providing reliable long-term storage and volatile memory providing fast temporary storage for redundancy operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different quality characteristics to different parts of the storage system. Non-volatile memory is used where reliability is critical for data persistence, while volatile memory is used where speed is critical for redundancy calculations and recovery operations. This local optimization of memory qualities resolves the contradiction between reliability and speed.

Inventive Principle:

Principle #3Local quality

2Reliability

If redundancy information is stored in non-volatile memory, then storage reliability is improved, but memory lifetime deteriorates due to frequent writes

Engineering Contradiction:

Improvestorage reliabilityVSAvoidmemory lifetime

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent segments the storage function by placing redundancy information in volatile memory, which has a different wear characteristics. This allows the non-volatile memory to be used primarily for data storage with fewer write cycles, thereby extending its operational lifetime while maintaining reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes volatile memory, which is faster but more susceptible to data loss without power, for storing redundancy information. This is acceptable because redundancy information can be recalculated from data items if needed, and the volatile memory's short retention characteristic is compensated by backup power sources or advance notifications.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Speed

If redundancy information is stored in volatile memory, then data retrieval speed is improved and latency is reduced, but reliability deteriorates due to power interruption sensitivity

Engineering Contradiction:

Improvedata retrieval speedVSAvoidstorage reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent implements beforehand cushioning by providing backup power sources or advance notifications to protect the volatile memory from power interruptions. This ensures that redundancy information stored in volatile memory is preserved under adverse conditions, mitigating the reliability concern while maintaining the speed advantage.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Ease of operation

If redundancy information is stored in volatile memory, then management tasks are simplified, but device complexity increases due to power protection mechanisms

Engineering Contradiction:

Improvemanagement simplicityVSAvoidsystem complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the redundancy information storage function from the non-volatile memory system and places it in a separate volatile memory subsystem. This extraction simplifies the management of redundancy operations by isolating them in a dedicated fast memory space, while the added complexity of power protection mechanisms is contained within this separate subsystem.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS20120254694A1Redundant storage in non-volatile memory by storing redundancy information in volatile memory

Publication Date: 2012.10.04 APPLE INC

AI summary

A method for data storage includes storing two or more data items in a non-volatile memory. Redundancy information is calculated over the data items, and the redundancy information is stored in a volatile memory. Upon a failure to retrieve a data item from the non-volatile memory, the data item is reconstructed from remaining data items stored in the non-volatile memory and from the redundancy information stored in the volatile memory.