Analysis and Performance Evaluation of Real Time Disk Scheduling Algorithms

Abstract

Real Time Disk Scheduling (RTDS) is an important for time critical (digital control,multimedia, signal processing and Telecommunication) applications. Traditionally, diskshave used seek optimization technique such as SCAN or SSTF for minimizing armmovement in serving I/O requests. Even though these techniques utilize the arm efficiently,they may not be suitable for real time environments since they do not have notion of time ordeadline in making a scheduling decision. In this dissertation, real-time diskscheduling algorithmsSCAN-EDF,EDFand CSCANareanalyzed in terms of disk track accessed, track traversed, track traversed order, and theaverage seek lengthfor the particular task set. A simulation model is developed which is coded in java programming language to assess the performance of the SCAN-EDF algorithm with comparison to EDF and CSCAN algorithms.The simulation results demonstrate that the proposed algorithm is superior to other existing algorithms.