作　　者： ; ; ; ;

机构地区： 江苏大学计算机科学与通信工程学院

出　　处： 《小型微型计算机系统》 2010年第12期2343-2347,共5页

摘　　要： 文件布局是文件系统的重要组成部分,维护了文件的逻辑位置到物理位置的映射关系.Redbud并行文件系统(RFS)舍弃了分布式文件系统常用的基于块的文件布局,提出一种基于扩展区间的文件布局方法,提高对大文件的顺序访问读写速度.RFS遵循"满足应用请求最低要求"的原则,即元数据服务器仅返回文件Layout中与应用请求对应的文件区间给客户端,能有效减少了客户端获取Layout的网络传输开销,提高系统的性能,并用空间连续分配策略及扩展区间实时合并策略,有效地提高了文件布局操作的速度.对比测试了RFS、EXT3和NFS对16GB大文件的操作性能,RFS随机读、随机写、顺序读、顺序写文件的吞吐率分别比NFS高47.5%、51.8%、65.6%和75.1%,RFS读文件的吞吐率略高于EXT3,RFS顺序写和随机写的吞吐率分别比EXT3高21.2%和15.4%,同时,RFS总的吞吐率呈线性增长,逼近实验环境的极限值200MB/s,结果表明,基于扩展区间文件布局的Redbud并行文件系统具有高性能. File layout which manages the mapping relationship between logical offset of file and physical address of storage device is important for a file system.Redbud parallel file system（RFS）discards block-based file layout that distributed file systems implement in common,and carries out extent-based file layout which fits for sequential read and write on large files.Following the principle of meeting the minimum requirements which means the metadata server only returns the layout which meets the applications request on the clients can decrease the overhead on network transfers and improve the system performance of RFS.Moreover,RFS adopts the strategy of space continuous allocation and the strategy of extents real-time merger during file layout operating that can speed up metadata operations.We compared the performance of RFS with that of EXT3 and NFS by sequential and random reading and writing a 16GB file.The throughput of RFS gets 47.5% and 51.6% higher than that of NFS on random reading and writing,while it gets 65.6% and 75.1% higher on sequential reading and writing.The throughput of RFS also gets a little higher than that of EXT3 on sequential and random reading,while it gets 21.2% and 15.4% higher on sequential and random writing.The total throughput of RFS grows liner till the limitation of the test environment about 200MB/s.Test results show that Redbud parallel file system based on extent-based layout can provide high performance.

关 键 词： 并行文件系统 并行文件系统 存储区域网 文件布局 扩展区间

领　　域： [自动化与计算机技术] [自动化与计算机技术]