Study on disk zoning for video servers

Without proper care of the disk zoning issue, one may suffer a great loss in both storage and bandwidth utilization for supplying video streams. In this regard, the authors propose two schemes, free-/spl pi/ and fixed-/spl pi/ schemes, in a unified framework of rearranging the zone layout in a logical manner. The free-/spl pi/ scheme can optimally utilize resources, but needs a complicated timing control. Whereas, the fixed-/spl pi/ scheme can achieve a slightly lower utilization with a simpler timing control compared to the free-/spl pi/ scheme. The fixed-/spl pi/ scheme is further applied to a multiple-disk platform. The variable bit rates of individual disks may cause dramatic aggregated bit rate fluctuation, so they propose a novel data placement policy termed skewed zone-major round robin (SZRR) to ensure a stable disk-bus bandwidth utilization. A file system employing the proposed schemes has been implemented on a PC server equipped with five SCSI-II disk drives. They demonstrate that the system is able to support up to 70 1.5 Mbps video streams simultaneously when a 20 second or so initial waiting time is allowed.