NTFS Junction Points

Junction Points (also commonly referred to as NTFS Junction or Directory Junction) are a type of reparse point which contains link to a directory that acts as an alias of that directory. Junction point work similar to a symbolic link but only for directories. Junction points even though being implemented closely as a symlink, is a Windows exclusive feature. The feature was first introduced in NTFS 3.0 that shipped with Windows 2000. While being similar to a symlink, its working is peculiar. In this article we will take a look at advantages, disadvantages and uses of a junction point. Since Junction Points are a type of reparse point, we would be comparing it with other reparse points to figure out advantages and disadvantages. Advantages of Junction Points :

• Directory Junctions were introduced in Windows 2000, and therefore is compatible with ever later iteration of windows (symlinks were introduced on windows vista).
• Takes less time to resolve.
• Does not require administrator privileges during creation (as opposed to symlinks).
• Stores absolute path of the target, therefore problems related to relative path doesn't exist.

Disadvantages of Junction Points :

• Does not support remote SMB or UNC paths.
• Only support directories.
• Only supported on Windows OS, leading to reduced usage due to incompatibility with other operating systems.

Usage of Junction Points :

• Junction points are used by the operating system to allow legacy Directory Paths on Windows, by pointing Junction points to the newer paths.
• Since Junction Points are dealt with at File system level therefore they could be used for path redirection, and therefore be used to point to non existent paths on a drive.
• Used as the defector way of Directory linking in Windows versions prior to Vista.