HDD Emulator Using DRAM for Server Blade Reliability

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Solution Overview

Problem

The mechanical hard disk drives in server blades are prone to failure due to spinning disks on bearings, leading to reliability issues and a need for more efficient data storage solutions in scalable server systems.

Innovation Solution

A hard disk drive emulator using dynamic random access memory (DRAM) with a controller for refreshing content and an input/output port to provide a standard HDD interface, allowing the DRAM to function as swap storage space within a computing system, thereby reducing reliance on mechanical hard drives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical hard disk drives are used for data storage in server blades, then data storage capacity is achieved, but reliability deteriorates due to spinning disks on bearings being prone to failure

Engineering Contradiction:

Improvehard disk drive reliabilityVSAvoidmechanical component complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical hard disk drive system with an electronic memory-based system. The HDD emulator uses a memory device (non-volatile or volatile memory) coupled with a controller to emulate hard disk drive functionality, eliminating spinning disks, bearings, and other mechanical components. This substitution directly resolves the reliability issue by removing the mechanical failure points while maintaining data storage and swap space functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a functional copy of the hard disk drive interface and operations using software and electronic components. The HDD emulator presents itself as a virtual hard disk to the operating system, copying the external behavior and interface of a physical HDD while using fundamentally different (non-mechanical) internal components. This allows the system to maintain compatibility with existing HDD-based systems while achieving improved reliability through electronic implementation.

Inventive Principle:

Principle #26Copying

2Productivity

If dynamic random access memory is used as swap storage space, then data swapping efficiency is improved, but data persistence capability deteriorates since DRAM is volatile memory

Engineering Contradiction:

Improvedata swapping efficiencyVSAvoiddata persistence capability

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the parameter of memory persistence by providing two implementation options: using volatile memory (DRAM) for maximum speed with no persistence requirement, or using non-volatile memory for persistence with slightly reduced speed. The controller manages the non-volatile memory to provide HDD-like functionality including persistence. This parameter change allows system designers to optimize based on whether speed or persistence is the priority, resolving the contradiction between swapping efficiency and data persistence.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7505890B2Hard disk drive emulator

Publication Date: 2009.03.17 COX COMMUNICATIONS INC

AI summary

A hard disk drive (HDD) emulator comprises a dynamic random access memory, a controller that refreshes content of the dynamic random access memory, and an input/output port coupled to the controller. The input/output port provides a hard disk drive interface. An operating system of a computing system in which the HDD emulator is installed uses the dynamic random access memory as a swap storage space.