unionfs-fuse

Userspace Unionfs File System

unionfs-fuse overlays several directory into one single mount point It first tries to access the file on the top branch and if the file does not exist there, it continues on lower level branches. If the user tries to modify a file on a lower level read-only branch the file is copied to to a higher level read-write branch if the copy-on-write (cow) mode was enabled.