A method for fast incremental replication of a file system. The method includes, at a data storage level, tracking file system status for a plurality of files by using a data structure inside respective inodes for the plurality of files, and at a file system level, tracking file system status for a plurality of files by using a file system mask structure. For all files present in a backup, a catalogue of the file path name and inode number is maintained on a source file system. During incremental backup, a source file system data structure enumerating a plurality of modified inodes is consulted. For inodes that have not been marked as removed or created, the file system mask structure that tracks modified portions is consulted to obtain a file incremental change and inodes. The method further includes performing incremental backup using the inodes that have been modified and appended.