【作者】 薛继东；

【导师】 王力；

【作者基本信息】 西安电子科技大学 ， 计算机软件与理论， 2004， 硕士

【摘要】 机群文件系统提供的文件访问效率对整个机群系统的性能有着至关重要的影响，MOSIX负载均衡机群系统利用抢占式进程迁移和直接文件系统访问(DFSA)机制，实现了机群节点间的负载均衡和资源的协调使用，MOSIX机群文件系统MFS通过在服务器节点进行全局唯一的缓存实现了单一节点一致性，提供了对DFSA机制的支持。但这种缓存方法导致MOSIX节点使用的传统Linux虚拟文件系统缓存策略不能很好的满足MFS缓存要求，对MFS的文件访问效率产生了影响。 本文首先分析了MOSIX中单节点使用的Linux虚拟文件系统缓存机制，对机群文件系统中的两类缓存模型：三层缓存体系结构和协作式缓存进行了详细的讨论；在对MOSIX及其机群文件系统MFS和DFSA机制进行深入研究的基础上，本文把协作缓存机制引入到MFS中，提出了MOSIX全局协作缓存(MGCC)模型，改进了MOSIX的缓存策略。MGCC模型的设计保证了与MOSIX原有的内存引导算法和DFSA机制不产生冲突，从而进一步保证了MGCC的有效性。文章最后对该模型的实现进行了探讨。更多还原

【Abstract】 The efficiency of file accessing in cluster file system plays an important role in the performance of the cluster system. MOS1X load-balancing cluster system is an enhancement of Linux. Through the preemptive process migration it can balance loads variatins in the resoures usage among the nodes in the cluster. Direct File System Access, a provision that allowing a migrated process to directly access files in the current loaction, is supported by MOSIX through the MOSIX File System(MFS). To make DFSA work, A single-node consistency is required, and MFS can support the requirement by caching the only block data on the file server in the cluster system, but the traditional Linux cache mechanism on the file server can’t provide enough buffer caches to both the local and the remote client processes. At the same time , there maybe have some nodes in the cluster with low load and their buffer caches aren’t used efficiently. On the analysis of Linux virtual file system, cache models in cluster file system, MFS and the mechanism of DFSA, the Paper import the provesion of Cooperate Caching to MFS and put forward the mechanism of MOSIX Global Cooperate Caching(MGCC), which can make all the buffer caches in the cluster cooperate when the cluster is working and make these buffer caches utilize fully, so the overall performance of the MFS can be improved. And the paper also describe the MGCC can work with DFSA and memory ushing algorithm harmoniously.更多还原