In order to adapt to the extensive VOD system, this paper brings up a hierarchical storage structure based on disk array and VCD library, analyses a scheduling algorithm called Round-Robin for VCD library as a tertiary storage system.

• 为适应大规模VOD系统的要求 ,提出了基于磁盘阵列和光盘库的层次化存储结构 ,并分析了 3级光盘库的RR节目调度算法。