Efficient Region Layouts for Region-based Video Servers Employing Multi-zone Disks

This paper investigates the implementation of video servers employing multi-zone disks. A multizone disk consists of a set of concentric disk zones with non-uniform storage capacities and data transfer rates. Superimposing a customized region layout on the top of such a disk is essential for facilitating the video server design and improving the disk resource utilization. This paper develops theories concerning the optimal region layouts for implementing the region-based data placement. Based on them, two efficient region layout algorithms are proposed, namely, the free-π scheme and fixed-π scheme. The former can achieve better resource utilization than the latter, but the latter requires a simpler timing control than the former. Extension of the fixed-π scheme to perform the disk striping in a disk array platform is also investigated. A spiral synchronization scheme is proposed to improve the system scalability by alleviating the disk bus congestion problem, caused by variable data transfer rates from individual disks. The analytical results reveal that the proposed schemes can effectively customize region layouts to achieve 85-99% resource utilization. By considering the region layout together with other design factors, an efficient configuration strategy is proposed for building a cost-effective server subject to the performance requirements of a target application.