一种面向视频播放系统的RAID并行预取技术及实现

随着视频数字化技术的广泛应用，视频播放系统中的存在“瓶颈”也日益突出，在分析视频存储系统磁盘阵列的I／O调度算法和在实际应用中视频数据的特点的基础上，提出一种面向视频媒体服务的RAID并行预取实时调度算法，它利用未来数据的可行预测性，预先将其从磁盘取入缓冲区，同时优化任务调度，使主机数据的回送和从磁盘预取数据同步执行，进一步提高了阵列的I／O吞吐率，用I／Ometer测试结果证明，新算法具有很好的性能。

A PARALLEL PREFETCHING METHOD IN RAID ORIENTED TO MEDIA SERVER

With the popular application of the video digital technology, the storage bottleneck of the video service system is becoming increasingly serious. Based on the analysis of the I/O scheduling algorithm of RAID and the characteristics of the video data, a new parallel prefetching real-time dispatch method for video media service is designed. It forecasts the next batch of data requested by the host and fetches the data from the disks to the buffer in advance. At the same time, it optimizes the tasks dispatching, which enables the two tasks to be executed in parallel: the task of returning the requested data to the host and the task of prefetching data from disks. It is seen from the result by I/O meter that the new method improves the performance greatly.