An Efficient Disk Scheduling Algorithm for Multimedia System Based on GSR Algorithm

Disk scheduling has an important role in QOS guarantee of soft real-time environments such as video-on-demand and multimedia servers. Since now, some disk scheduling algorithms have been proposed to optimize scheduling disk requests. One of the most recent algorithms is GSR. GSR improved the disk throughput by globally rescheduling scheme for real-time disk requests. In this paper, we propose a new algorithm based on GSR that is called IGSR (Improved GSR). The proposed method improves throughput and decreases the number of missed deadline requests by employing FTS (Feasible Tasks Sequence). Simulation results showed IGSR decreased the number of missed deadlines 50% and increased disk throughput 12% in compare with GSR. Also, when the input is infeasible, IGSR provided about 40% more feasible output schedules.