Coded Seeking for Hard Disk Drive Access Time Reduction

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Solution Overview

Problem

Hard disk drives with moving mechanical parts face bottlenecks in data access speed, which existing I/O latency reduction algorithms fail to adequately address, leading to inefficiencies in data retrieval times.

Innovation Solution

Implementing a coded seeking technique that uses network coding to identify and retrieve coded blocks closest to the read head position, reducing average physical drive movement and seek times by generating linear combinations of native data blocks and storing them as innovative coded blocks on disk platters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If conventional seeking methods are used to retrieve individual data blocks, then data can be accessed from any location on the disk, but average access times are long due to physical movement of read/write heads and actuators

Engineering Contradiction:
Improvedata access timeVSAvoidphysical movement requirement
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

The patent replaces the mechanical seeking system with a coding-based information retrieval system. Instead of physically moving read/write heads to specific disk locations, the system uses coded blocks that contain linear combinations of original data blocks. The controller retrieves coded blocks based on information content rather than physical position, substituting mechanical movement with computational operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces coded blocks as intermediaries between the stored data and the retrieval process. These coded blocks contain linear combinations of original data blocks and serve as mediators that allow the system to access information without direct physical seeking. The coded blocks act as a layer that transforms the retrieval problem from a physical positioning task to an information-based selection task.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If read-ahead algorithms are used to predict and exploit common access patterns, then some access latencies can be reduced, but they fail to keep up with growing demands for I/O access speed increases

Engineering Contradiction:
ImproveI/O access speedVSAvoidalgorithm effectiveness
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent fundamentally changes the parameter being optimized from physical disk position to information content. Instead of predicting access patterns based on temporal sequences, the system transforms data into coded blocks where any subset of sufficient coded blocks can reconstruct the original data. This changes the optimization parameter from 'which block to access next' to 'which coded blocks contain the necessary information'.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2972751B1Method and apparatus to reduce access time in a data storage device using coded seeking
Publication Date: 2018.11.28 MASSACHUSETTS INST OF TECH
  • EP2972751B1 patent drawingFigure 1
  • EP2972751B1 patent drawingFigure 2
  • EP2972751B1 patent drawingFigure 3

AI summary

Data blocks to be stored on a disk-based data storage device (e.g., a hard disk drive, etc.) are coded together to form a plurality of linearly independent network coded blocks. The network coded blocks are then stored on the data storage device. Coded seeking may then be used to retrieve the original data blocks from the data storage device in a time-efficient manner. A read request may be sent to the data storage device requesting an innovative coded packet associated with the original data blocks. In response to the read request, the data storage device may read an innovative coded packet from the disk that is closest to current position of a read element of the device.