Towards Higher Disk Head Utilization: Extracting "Free" Bandwidth From Busy Disk Drives

Abstract

Freeblock scheduling is a new approach to utilizing more of disks' potential media bandwidths. By filling rotational latency periods with useful media transfers, 20?50% of a never-idle disk's bandwidth can often be provided to background applications with no effect on foreground response times. This paper describes freeblock scheduling and demonstrates its value with two concrete applications: free segment cleaning and free data mining. Free segment cleaning often allows an LFS file system to maintain its ideal write performance when cleaning overheads would otherwise cause up to factor of 3 performance decreases. Free data mining can achieve 45 - 70 full disk scans per day on an active transaction processing system, with no effect on transaction performance.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 2000
Accession Number
ADA382318

Entities

People

  • Christopher R. Lumb
  • David F. Nagle
  • Erik Riedel
  • Gregory R. Ganger
  • Jiri Schindler

Organizations

  • Carnegie Mellon University

Tags

Communities of Interest

  • Human Systems
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Access Time
  • Algorithms
  • Bandwidth
  • Computations
  • Computer Science
  • Computers
  • Data Mining
  • Databases
  • Detection
  • Firmware
  • Information Science
  • Network Science
  • Organizational Realignment
  • Sampling
  • Scheduling (Production)
  • Simulators
  • Workload

Fields of Study

  • Computer science

Readers

  • Computer Vision.
  • Database Systems and Applications
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering

Technology Areas

  • AI & ML