Design and Implementation of an Efficient Multi-version File System

The benefit of multi-version file system is high reliability. File versioning can be used for file-oriented recovery from deletion and limiting exposure to data losses during file system failure. The problem is that accesses to versions in the distant past may be prohibitively expensive. We adopt the hierarchical architecture in version space to reduce the time spent on search; We present a new structure named red black tree embedded in inode to organize versions of a directory and another new structure named red black tree with weight and link to build index for versions of a file. Using aforementioned technologies, we implement an efficient multi-version file system named thvfs. The experiment results show that the average time of searching old versions in thvfs is 34.4% lower than that in ext3cow, the famous multi-version file system.