基于通用计算机网络实现磁盘镜像

IMPLEMENTING DISK MIRROR BASED ON GENERAL NETWORK

随着科学技术的发展，特别是人们需求的提高，对计算机系统的安全性和可靠性提出了更高的要求．顺应这一发展，本文提出了一个基于通用计算机网络实现磁盘镜像的系统．在UNIX中，应用程序通过文件系统调用接口完成对磁盘文件的操作．我们通过对文件系统调用的截取和功能扩充，实现了磁盘镜像．由于是在UNIX系统的核心空间中实现，因此镜像系统对于用户空间的应用程序来说是透明的．同时我们采用NFS来实现该系统的网络通信，这样不但可以减小系统实现的复杂程度，而且能够提高系统的可靠性．本文详细描述了磁盘镜像系统的设计思想、实现方法和主要数据结构．并对该系统进行了性能测试．最后作者说明了该系统的进一步发展方向．

It is necessary for a computer system to have higher security and reliability in response to the development of science and technology, in particular higherapplication requirements. To go with the tide of historical development, this paperpresents a system which implements disk mirror based on general network. InUNIX, applications access disk files via system calls of file system. Therefore, diskmirror based on general network can be implemented by intercepting the systemcalls of file system and extending their functions. The disk mirror system is trans-parent to applications that are in user address space, for it is implemented in kerneladdress space- Adopting NFS as the communication layer, not only the complexityof this system is reduced but also the reliability of this system is improved. Thispaper discusses the design idea, approaches for implementation such as technique ofaccessing kernel data,and key data structures in detail. Some performance measure-ments on'this system are also given. The results show that this disk mirror systemachieves its design goal. At the end of this paper, the trend of development of thissystem in the future is proposed.