Disk striping strategies for large video-on-demand servers

Abstract

The storage structure of videos on disks affects the number of concurrent users a video- on-demand system can support and hence the average waiting time. In this paper, we propose a phase-based striping method which has the desirable characteristics that it guarantees the maximum waiting time. We also develop a data replication scheme to further reduce the average waiting time of the phase-based method. These two schemes, together with the conventional sequential striping scheme, are then employed to optimize the waiting time of videos based on their access pattern. Simulations were conducted using a video server containing 36 videos under different loading and hardware configurations. The results show that such optimization can reduce the waiting time significantly. The use of replication method could further improve the server performance by over 25%. The overall results indicate that with limited resources, the use of phase-based striping method with replication is preferable under heavy loads.