Continuous Display of Video Objects Using Multi-Zone Disks

Video servers are expected to play an important role in a number of application domains e g library information systems entertainment industry scienti c applications etc A challenging task when implementing these systems is to ensure a continuous display of audio and video objects If special precautions are not taken the display of an object may su er from frequent disruptions and delays termed hiccups A second challenging task is to con gure a system to meet the performance requirements of an application its desired number of simultaneous displays and the waiting tolerance of a display For applications with large data sets e g video servers magnetic disks have established themselves as mass storage device of choice A technique to increase the storage capacity of disks is zoning A side e ect of zoning is that it introduces a disk drive with variable transfer rates This paper describes techniques to support a continuous display of video objects using a multi zone disk drive As compared to previous approaches the proposed techniques harness the average transfer rate of the magnetic disk instead of its minimum transfer rate In addition we describe a con guration planner that logically manipulates the zoning information of a disk drive to support the performance criteria of an application This research was supported in part by the National Science Foundation under grants IRI IRI IRI NYI award and CDA and a Hewlett Packard unrestricted cash equipment gift