Directory junctions NTFS reparse point

directory junctions similar volume mount points, reference other directories in file system instead of other volumes. instance, directory c:\exampledir directory junction attribute contains link d:\linkeddir automatically refer directory d:\linkeddir when accessed user-mode application. function conceptually similar symbolic links directories in unix, except target in ntfs must directory (typical unix file systems allow target of symbolic link type of file).

directory junctions (which can created command mklink /j junctionname targetdirectory , removed rmdir junctionname console prompt) persistent, , resolved on server side share same security realm of local system or domain on parent volume mounted , same security settings contents content of target directory; junction may have distinct security settings. unlinking directory junction not delete files in target directory.

some directory junctions installed default on windows vista, compatibility previous versions of windows, such documents , settings in root directory of system drive, links users physical directory in root directory of same volume. hidden default, , security settings set windows explorer refuse open them within shell or in applications, except local built-in system user or local administrators group (both user accounts used system software installers). additional security restriction has been made avoid users of finding apparent duplicate files in joined directories , deleting them error, because semantics of directory junctions not same hardlinks; reference counting not used on target contents , not on referenced container itself.

directory junctions soft links (they persist if target directory removed), working limited form of symbolic links (with additional restriction on location of target), optimized version allowing faster processing of reparse point implemented, less overhead newer ntfs symbolic links, , can resolved on server side (when found in remote shared directories).