摘要： 研究Linux 系统中多路径磁盘过滤驱动程序的设计和实现。驱动程序将物理磁盘的多路径封装为一个虚拟设备。虚拟设备的I/O请求转发到磁盘设备上执行，由路径选择算法将主机的负载均衡地分配到各路径上。当路径发生故障时由驱动程序将失败的I/O 请求切换到其它路径，屏蔽了路径故障。驱动程序利用多路径改善了主机的I/O 性能，提高了系统的可用性。

关键词: 容错；高可用性；负载均衡；Linux

Abstract: A multi-path disk filter driver for Linux is designed and implemented to represent the plurality of data paths to the I/O device as a single virtual device. The I/O requests for the virtual device are redirected to selected disk devices, and the I/O load is distributed among multiple paths by the path selection algorithm. If one path fails, the incomplete I/O requests are redirected to the survival paths so the path failure is isolated. The filter driver increases the data access throughput and availability by using multiple paths.

Key words: Fault tolerance; High availability; Load balance; Linux