视频服务器的磁盘I/O调度算法

Disk I/O Scheduling Algorithm of Video Server

讨论了视频服务器的Ｉ／Ｏ 调度问题．通过对磁头移动和旋转延时的优化， 得出了双向扫描（Ｂｉ－ＳＣＡＮ）调度算法．对需要同时支持多种视频速率的异构系统， 在Ｂｉ－ＳＣＡＮ算法的基础上，给出了固定数据长度（ＣＤＬ）和固定时间长度（ＣＴＬ）两种调度方案的接纳控制条件．通过模拟实验比较了这两种调度方案的性能，

I/O scheduling of video server is discussed.Through the optimization of the motion of disk arm and the rotation latency,we get the Bi SCAN scheduling algorithm.For heterogeneous system,which is required to support multi rate videos, we put forward CDL and CTL scheduling schemes based on Bi SCAN.And conditions of admission control of theses schemes are offered.Simulations are performed to test the performance of them.At last an improved CDL scheduling scheme is proposed which is based on bucket control.