An efficient data placement and retrieval scheme of zoned-disks to support interactive playout for video servers

Of late, zoning technique has been applied on modern disks to increase their capacities. As a result, a disk is partitioned into several zones with various sectors/track ratios. Another effect of disk zoning is that disks have higher transfer rates (bandwidths) on outer zones than on inner zones due to the disks spinning at a constant angular velocity. In this paper, a compensatory region-based data placement is proposed to efficiently utilize the disk bandwidths of zoned-disks. Due to the same reading time of a data block, more data can be read on outer zones to compensate for the insufficient read on inner zones, which can significantly improve the disk throughput. From simulation results and the performance evaluation of the prototype, the disk throughput can be promoted by 25%35% compared with that of the original region-based data placement scheme. In addition, a frame converting strategy is designed to reconstruct the video data. With the frame converting technique, the proposed scheme can facilitate the interactive operations of video playout for video servers.