蓝鲸机群文件系统文件layout设计与实现

维护文件逻辑位置到物理位置映射关系的文件布局是文件系统的重要组成部分。针对蓝鲸海量机群文件系统中文件的条带分布特性，分析了目前普遍采用的三级间接地址文件布局和扩展块段文件布局的优缺点。有效结合三级间接地址文件布局避免查询、直接映射的优点和扩展块段文件布局映射高效、空间占用少的优点，提出了一种新的固定长度扩展块段文件布局，并在小文件环境对其进行了优化改进，提出了幂次长度扩展块段文件布局。实验测试结果表明该文件布局可以有效适用于蓝鲸机群文件系统，达到了预期效果。该文件布局同样适用于其他采用条带机制的文件系统。

Design and Implementation of File Layout in Blue Whale Cluster File System

File layout,which manages the mapping relationship between logical offset of file and physical address of storage device,is important for a file system.The commonly used triple-indirect and extent-based layouts are not fit for cluster file systems that use stripe to improve performance,such like BWFS.A novel fixed-length extent-based layout was presented and improved as power-length extent-based layout especially for small-size files.The presented layout effectively absorbs the direct-mapping advantage of t...