What is hardlink

Create a free Team What is Teams? Learn more. What is the difference between NTFS hard links and directory junctions? Ask Question.

Asked 12 years ago. Active 7 months ago. Viewed 71k times. The title says it all When do I use one and when do I use the other? Improve this question. James Mertz Vilx- Vilx- 3, 6 6 gold badges 28 28 silver badges 34 34 bronze badges. According to Microsoft documentation, there are three distinct categories: Hard link: msdn.

Add a comment. Active Oldest Votes. Hardlinks have to be on the same physical and logical volume. They are useful for: reducing path lengths since Windows just supports characters or so. Same caveats, too! And then there are symbolic links which can go across networks , shortcuts and PIFs and Also some information from Microsoft itself : Basically, they're saying to use hard links only for files within the same volume disk drive letter and junction points only for directories on the same computer they can span across different local volumes.

Improve this answer. Forethinker 2 2 gold badges 8 8 silver badges 25 25 bronze badges. In the syscalls the reparse point seems to be handled by both.

NTFS returns the reparse point in response to some open file call - instead of opening the file, and then the windows api layer "reparses" it opens the new file name.

A reparse point causes a file system filter to be called according to a tag in the reparse point data - basically it's a way to cause driver code to be called when a file is attempted to be opened.

Quick Definitions: Symbolic link: A link to a file or directory on the same or different volume drive letter or even to a remote file or directory using UNC in its path. Default is a file symbolic link. Link specifies the new symbolic link name. Target specifies the path relative or absolute that the new link refers to. Community Bot 1.

File and folder are mostly interchangeable as far as NTFS goes. Josip Medved Josip Medved 8, 1 1 gold badge 28 28 silver badges 41 41 bronze badges. Sorry, junctions and soft links are not the same thing for NTFS. However, there is further distinction between junction aka soft-link and symbolic link, but I haven't went into details here.

For those interested, details can be found in Windows documentation at msdn. Since Windows Vista, there are both NTFS junctions can only be pointed to directories and Unix-style symlinks can point to literally anything. Hard links are more persistent in connecting a directory entry or file to the same memory space. Hard links resist file replacement. Although some refer to soft links as pointers or shortcuts, experts point out that both hard links and soft links are technically pointers, but that hard links are more persistent pointers.

However, if it is a soft link, the link would then go to a non-existent file. By: Justin Stoltzfus Contributor, Reviewer.

By: Satish Balakrishnan. Dictionary Dictionary Term of the Day. Machine Intelligence. Techopedia Terms. Connect with us. Delete files not anymore available in Source from Destination. DeLorean Copy is a way of creating incremental backups by using a combination of hardlink clone and Smart Copy. Phase 1: Initial SmartCopy. The folder Source t is initially copied to InitialBackup. This is shown by the blue arrow. Changes happen.

Phase 2: Hardlink Clone. Phase 3: Mirror. Mirrors the folder Source to Backup1. Volume Mount Point Support. As described in the backgrounders section NTFS maintains a reference count for each data stream object how many NTFS directory entries refer to that objects.

This additional tab only shows up in the file or directory properties, if the file or directory is a hardlink, junction, volume mountpoint or symbolic link, otherwise this tab is not available. LSE supports the creation of symbolic links. Symbolic Links can also be created between directories.

Overlay icons for Symbolic Links can also be customized. Enumeration of Hardlinks. Simply select a hardlinked file and select Properties from the action menu: The Hardlink Enumeration functionality is also available via command line from ln.

Change Symbolic Link Privilege. Map a network share Pick a file from that share Drop the file as Hardlink within the same share A Hardlink has been created, which can be easily verified Furthermore SMB1. Currently the reference count of a hardlink is reported via SMB1. LSE supports removable media, which have been formatted with NTFS, to create all kind of features it does for fixed drives too.

Explorer supports pathnames up to characters, thus limiting all applications to that length for pathnames. Third Party FileSystems. Link Shell Extension has built in overlay icons for junctions, hardlinks and symbolic links. Overlay Icon Sometimes it might be useful to totally disable certain overlay icons from Link Shell Extension, which can be acchieved by ticking the checkbox for overlay icons. Hardlinks are a feature common to many Unix based systems, but are not directly available with Windows.

Hardlinks can only be made on NTFS volumes, under the supported platforms. The Pick Link Source and Drop This also happens, if you select source files on a network drive, or select a file as destination, etc. There is an OS limit of creating more than hardlinks per file. This is less known, but it is there. ReFs does not support hardlinks. Q : However the value of the reference count is not updated when hardlinks are deleted.

That is, when I add new hardlinks the value increases properly, but when I delete hardlinks, the value does not change. Is that a bug? Or there is a way of refreshing the Windows Explorer? I'm wondering do you know why this might be - could it be my otherwise quite normal computer! Is there a way to prevent this? That is, for example, is it possible to automatically delete the junction points if the associated source is deleted?

Or, is it possible to have a program prune such orphaned junctions afterwards? What's wrong? Q : I have created a symbolic link to an. Check the path and try again.

Q : I double click on a symlink in explorer, which e. See also Symbolic Link Type Changed Q : The overlay icons do not show up A: The number of different icon overlay handlers that the system can support is limited by the amount of space available for icon overlays in the system image list. Q : I'm trying to store Dropbox files only on removable storage instead of the internal gb of storage. My DropBox already contains lots of files. How do I accomplish redirecting the dropbox folder to the removeable storage?

I cannot remember if this is expected or not? Q : I only changed the attribute of a file, even the timestamp and content are the same, but --delorean copies the file instead of linking to the old backupsets and just changing the attributes in the current backup set. Q : Broken Junctions with non-existent targets have their overlay icons displayed, but right clicking on them in Windows Explorer of Windows7 x64 SP1 and choosing "Properties" does not bring up the "Link Properties" tab.

Consequently the information where the broken Junction is trying to point is not accessible and cannot be corrected manually. Make sure the path and file name are correc. Version 4. Version 3. German Translation of Documentation. Progress bar prediction has been improved. Link ShellExtension now maintains its chocolatey package. Link ShellExtension is public on gitlab.

Reboot Explorer. Lots of strings very wrong. Introduced with 3. Improved menu hydraulics, e. Adapted check for Redistributables to VS and Windows Introduced with Unmount volume did not work, when elevation was needed. New Windows 10 screenshots for docu and docu streamlining. UAChelper mixed up relative and absolute link creation.

Introduced with Added Ukranian localization, Finished localisation for missing texts Cross Drive Drops didn't work. Introduced with Properties Dialog could cause a crash on changing junction targets Autorename had a flaw when having more than 9 files with same name in a directory Backup mode was broken. Fixed the misconception. What a mess LSE is on gitlab. For now only private, but hope to change this soon.

SmartMirror in LSE had problem with nested reparse points The symbolic replacement mechansism was broken for the elevated use-case. Caused by 3. Basically everything compiled smoothly except for the heap, thus This was neccessary, but also a big performance gain.

Memory allocation is 2 times faster, and memory deletion is 10 times faster. Memory allocation is crucial for the core of ln. With Windows 10 LSE shows flat icons for symlinks, hardlinks and junctions.

Thx to Yaroslav for the icons. The overlay icon for Junctions didn't show up at all with Windows 7. The property dialog for hardlinks, when used on substituted drives, showed wrong path for the siblings. Third party filesystems can be configured. Added Greek localization. Thanks to George Malamas! SmartMove didn't work when Backup Mode was enabled.

Runs again with Windows Flaw introduced with 3. NTFS filesystem fragmentation decreased and thus copying should be faster Cancel works when pressed during copying of large files. Creation of hardlinks in UAC protected folders caused an error message, even if the hardlink was created.

The progress bar didn't increase properly during Smartmirror if the files were the same. In a rare situation only the first symbolic link of a smart-copy was linked incorrectly. The Auto Rename functionality didn't work in rare situations. Fixed a crash, when files were dropped from Bandzip to the desktop. Added localization for Korean. Thanks to Mireado from Korea! On Windows10 systems which have been upgraded from Windows7 the enumeration of hardlinks siblings via the property page takes very long.

Prerequisites install not needed with Windows 10, thus do not check for prerequisites under Windows Prerequisites still checked by installer with Windows Japanese translation for LSEConfig.

The target of mountpoints can be changed from Link Properties. WindowsXP: Symbolic links across drives didn't work. WindowsXP: Symbolic links between very long path didn't work. WindowsXP: Lots of tweaks here and there. Very Nasty, but no dataloss caused. LSE elevates the creation of hardlinks in system protected directories, e. LSE now offers all its function also in the Library folder. If enabled LSE summarizes the ouptut of operations in a log file.

Symbolic links to mapped network drives can be created now via LSE. The check for prerequisites during install is more accurate aka takes mfc During un-install it is also checked if the hardlinkshellext.

Fixed a problem during SmartMirror when a directory changed into a file or vice versa from one mirror to the next and had exactly the same name.

The OS Version detection during installation went wrong on certain machines causing symlinke. The eunmeration of hardlink siblings didn't work under XP, when the root dir of a drive had to be traversed.

Tested with Windows8, and thus updated the documentation. The x64 version now contains also a 32bit version in one unified install. Deinstallation left over a few registry keys.

During installation not all processes were detected, which blocked the installation. Added a Swedish localisation. Added a Turkish localisation. Thanks to Memet. Added a Czech localisation. Thanks to Ashus Added a Slovak localisation. Draging from or Droping to zipped folders caused an explorer crash. LSEConfig localized to French. Columnprovider shows now shrinked path for junctions if the path is longer than 32characters.

Nested junctions and symbolic links aka junctions on junction on junctions Smartmove had problems with relative symbolic links in rare situations. Italian translation updated.

Support for symbolic links under Window XP. Can handle subst. Overlay Icons for symbolic links under Window XP are available now. Fixed a few bugs related to WindowsXP and symbolic links handling. Fixed a problem with the creation of absolute symbolic links to directories.

The installer came up with Chinese as default installation language. Replace Symbolic Link failed when not elevated. Replace Symbolic Link always created absolute symbolic links regardless of the settings when not elevated. Drop Symbolic Link sometimes did not create absolute links when needed in certain situations.

The installer now shows the language of the installed OS as default. The target of the Symbolic Liks or Junctions can be edited in the properties dialog.

Non administrators could not create symbolic links. With XP and the symlink driver installed the Delete Junction menu didn't show up. Introduced new Heap Manager Rockall for x64 and x86 builds to gain performance. Russian translation updated. Installation notifies about already running processes, which would make LSE installation fail, because they have loaded dlls from LSE.

Fixed issue with Windows 8 installation. Symbolic Link Icon Overlays installation in registry was wrong, causing problems with the green arrow for symlinks. Added Smart Mirror. The configuration tool does not restart explorer for minor changes to the settings. Symlinks creation resulted in absolute symlinks even if creation of syminks was specified as relative, if their common ancestor was a root dir.

Symbolic Links now have an overlay icon. Added a configuration tool for LSE options Added a priority level for the indidual overlay icons. Added an option to switch off overlay icons totally for each type of overlay. Overlay icons can be disabled. Documented how the install directory can specified when using silent un install. The menu hydraulics have been reworked, so that it is decided early to only show menu for chioces, which are really possible.

Tranparency glitches in the Junction overlay icon have been fixed. LSE shows a dialog box whether explorer should be restarted or not during non silent installation. Thanks to Marcio R. Fixed flaws of the automatically renaming feature with respect to directories under W7.

Overriding custom overlay icons under HKCU was flawed. Hardlink Clone now restores the attributes of cloned folders. Smart Move progress bar showed a wrong caption text.