The NTFS file system
implemented in NT4, Windows 2000, Windows XP, Windows
XP64, and Windows7/8/10 supports a facility known as hard links
(referred to herein as Hardlinks). Hardlinks provide
the ability to keep a single copy of a file yet have it
appear in multiple folders (directories).
They can be created with the POSIX command
ln
included in the Windows
Resource Kit, the fsutil command utility
included in Windows XP or my command line
ln.exe utility
Thus, using standard
Windows facilities Hardlinks can only be created at
the command prompt, which can be tedious, especially
when Hardlinks to multiple files are required or when
one only makes occasional use of Hardlinks.
Support for Junctions in standard Microsoft software
offerings is even more limited than that offered for
Hardlinks.
Link Shell Extension (LSE) provides for the creation of
Hardlinks
,
Junctions
,
Volume Mountpoints
, and Windows7/8's
Symbolic Links,
(herein
referred to collectively as
Links) a folder cloning process that utilises
Hardlinks or Symbolic Links and a copy process taking care of Junctions, Symbolic Links, and Hardlinks.
LSE, as its name implies
is implemented as a Shell extension and is accessed
from Windows Explorer, or similar file/folder
managers. The extension allows the user to
select one or many files or folders, then using the
mouse, complete the creation of the required Links -
Hardlinks, Junctions or Symbolic Links or in the case
of folders to create Clones consisting of Hard or
Symbolic Links.
LSE is
supported on all Windows versions that support NTFS
version 5.0 or later, including Windows XP64
and Windows7/8/10. Hardlinks,
Junctions and Symbolic Links are NOT supported on FAT
file systems, and nor is the Cloning and Smart Copy process
supported on FAT file systems.
Within this document the terms action button and
action
(pop up) menu
are used to refer what are often referred to
as the right mouse button and the pop up menu that is displayed
when that mouse button is pressed (often referred to as the
context menu). Recognising that people swap the usage of their
mouse buttons, Microsoft refer to the primary and
secondary
mouse buttons. We prefer to refer the mouse buttons as the
Select button and
the Action button;
and rather than terms such as Context Menu, Shell Menu, Right
Mouse Menu we use the term Action menu.
The current user must have administrator privileges in order to install the software.
LSE is installed by executing the install program
(HardLinkShellExt_$(platform).exe).
Follow the instructions issued by the program, there are no mandatory
inputs required during installation, it is possible to
change the location into which LSE is installed, the
default is
C:\Program Files\LinkShellExtension
During installation Explorer.exe has to be restarted to make Link Shell Extension active.
This means that all pending operations with explorer.exe are interrupted, but with the
interactive install you can decide to postpone the explorer.exe restart. A dialog box
will give you the choices during installation.
Some command line switches can be passed during install, so that a silent install via .bat file
can be acchieved.
Silent install
/S pops up no prompts during install. If the /S switch is used, explorer.exe will be restarted after installation, to make Link Shell Extension
active immediately.
Specify Language
/LANGUAGE passes the language in which LSE shows up. e.g.
Currently English, Chinese, Czech, French, German, Greek, Italian, Japanese, Korean, Polish, Portuguese, Russian, Slovak, Spanish, Swedish and Turkish are
available as valid parameters for the /Language switch.
Specify Directory
When using the silent install a directory can also be specified with the /D switch e.g.
If the /S switch is used during uninstall, explorer.exe will be restarted after uninstallation, to make Link Shell Extension
inactive immediately.
No Check for VcRedist
On some Windows10 machines, there is no need to install the vcredist, or worse: VcRedist can not be installed, but is somehow already on the system.
To overcome this the /noredist switch can be passed via command line. e.g.:
Pick Link
Source
causes the selected files to be "stored" as the
source for the Hardlinks that you want to
create.
To create the
Hardlinks a destination folder must be chosen, by clicking
the mouse action button on the destination folder a menu
will pop up, which will include the entry -
Drop
HardLink
Choosing Drop HardLink will create
the Hardlinks in the selected destination folder.
Overlay Icons for Hardlinks
To help distinguish hardlinks folders from normal files, an overlay icon is implemented
on hardlinks that shows a red arrow icon under the folder.
Overlay icons for Hardlinks can also be customized.
In Windows 2000 and XP
Hardlinks can also be dropped via an Action button
click in the "white space" of Windows Explorer's
right pane and choosing Drop HardLink from the
popup menu. It should be noted this feature is
only guaranteed to work in Windows Explorer;
many Explorer replacements implement an application
specific white space action menu that is not readily
accessible from general purpose shell extensions such
as LSE.
When doing an Action button click in the destination folder
background, in addition to the Drop HardLink option there is the
possibility to Cancel Link Creation
entry.
Since LSE supports Junction,
Clones and with Windows7/8/10 Symbolic Links,
when one or more folders are selected as the Source Links they can be dropped in several forms.
To avoid crowding the popup
menu, a submenu is provided that contains the different types of Links applicable to
folders.
Creating Hardlinks via drag and drop
is supported, after selecting one or more files you can
drag them to the destination folder with the Action button
held down; when it is released choose HardLink Here
from the action menu to create the Hardlinks of the
selected files in the destination
folder.
Files can be hard
linked to the same folder as the source folder. Because two
directory entries cannot have the same name, LSE uses
'$filename - Hardlink.$ext' as the name of the the new
link.
With Windows XP this behaviour is different and LSE
behaves under XP accordingly: 'HardLink of $filename'
LSE uses
the same hydraulics as explorer when it comes to multiple
'$filename - Hardlink': It uses numbers to enumerate the
multiple hardlinks of one file in the same directory, e.g.
$filename - Hardlink (2).$ext.
With Windows XP this behaviour is different and the names are generated
like 'Hardlink of $filename (2).
The Auto Rename mechanism is also used when Junctions, Hardlink Clones,
Symbolic Links, Symbolic Link Clones, Mountpoints or Smart Copies are created
in the same directory.
Junctions
are a feature of NTFS
version 5.0, they provide for the creation of
linkages among directories, Junction were not
supported in NTFS Version
4.0
Junctions
are created in the same way as Hardlinks, except that the
Source Link is a folder rather than a file. Select a
folder, click the right mouse button, choose
Pick Link
Source
from the action menu, navigate to the
destination folder, click the action button, open the
submenu Drop As ... and select
Junction:
Junctions are marked
with a small piece of chain below the folder
icon.
Junctions can also be
created via Drag and Drop when the selected folders are
dragged with the action button pressed to a destination
folder; when the right mouse button is released, select the
Drop Here ... submenu and then
Junction.
Junctions can be
deleted by using the Delete commands from Explorer as
usual, if Link Shell Extension is installed, because
Link Shell Extension implements a so called CopyHook handler, which
intercepts Explorers Delete commands, and thus fixes
Explorers problems with junctions.
Link Shell Extension changes Delete commands from Explorer
on Junctions to unlinking Junctions, and not deleting
the content within a junction, which seems most logical.
Windows7/8/10:
With Windows Vista & Windows7/8/10 explorer is natively aware of Junctions,
and no interception or CopyHook handler is necessary, Explorer
simply works out of the box with junctions. This is also the reason why the
Delete Junction menue does not show up on Vista and Windows7/8/10.
To show the origin of a junction, the reference column of a junction shows
the path to which the selected junction links.
Junctions are a
powerful feature, but can also be a dangerous feature without
Link ShellExtension precautions under Windows Version < Windows Vista.
Nativly Explorer shipped with < Vista becomes unstable if you use normal delete or
rename functions on junction folders. Windows Explorer will
always terminate abruptly and depending on system settings,
Windows XP may do likewise.
Overlay Icons for Junctions
To help distinguish junction folders from normal folders, an overlay icon is implemented
on junctions that shows a small three link chain icon under the folder.
Overlay icons for junctions can also be customized.
Junctions can span network drives as long as the target is a mapped network drive.
Unfortunately Junctions, which have a UNC Path as target, can be created
with LSE, but even Vista seems to contain a bug, which prevents it from
dereferencing a UNC Path in a junction, even if LSE correctly sets up
the reparse info for UNC junctions. When a UNC target junction is
double clicked in explorer the error ERROR_INVALID_REPARSE_DATA(4392), will
show up and tell you that the info in the reparse point is illegal, even if
it is not.
@Microsoft: Why didn't you enable this feature for junctions, even if the syntax
for UNC junctions is defined: \??\UNC\server\share. Any help appreciated.
With Vista and Windows7/8/10 some folders, e.g. c:\Program Files needs elevation for junctions
beeing created in. This is why the famous UAC dialog must be acknowledged.
To be exact: Only the creation of directories needs elevation in such situations, but creating
an empty directory is a vital part of creating a junction. The DeviceIoControl(), which
does the real work in creating junctions would work without elevation.
Link Shell Extension can change the target of an existing Junction,
Symbolic Link or MountPoint either via Pick/Drop or Drag and Drop.
To use this feature simply select an existing directory as
Link Source and drop it over an already existing Junction/Symbolic Link/Mountpoint.
By selecting the 'Drop as ... Replacement Junction/Symbolic Link/MountPoint'
from the action menu, the target of an already existing Junction/Symbolic Link/MountPoint
is replaced by the newly picked target.
The same can be achieved via Drag an Drop for Symbolic Link Directories, Junctions and Mount Points, but not
for Symbolic Link Files. Symbolic Link Files have to be repaired by the 'Pick Link Source',
'Drop as ... Replacement Symbolic Link' repair alternative.
When the backup mode is selected the ACLs of the Junction/Symbolic Link/MountPoint are preserved.
Link Shell Extension can copy an existing Junction,
Symbolic Link or MountPoint either via Pick/Drop or Drag and Drop.
To use this feature simply select an existing Junction, Symbolic Link or MountPoint as
Link Source and drop it over an already existing directory.
By selecting the 'Drop as ... Junction/Symbolic Link/MountPoint Copy' from the action menu, the
Junction/Symbolic Link/MountPoint is copied to the target and the relation is adjusted
The same can be achieved via Drag an Drop for Symbolic Link Directories, Junctions and Mount Points.
When the backup mode is selected the ACLs of the Junction/Symbolic Link/MountPoint are preserved.
Smart Copy creates a copy of the directory
structure from the source location to the destination, but it preserves the inner
hardlink structure and inner junction/symbolic link relations of the source, and
recreates this inner hardlink structure and inner junction/symbolic link relation
at the destination location:
With hardlinks it behaves as follows:
By closely looking at the above picture one can
find three different types of files:
Normal Files
The file B is a normal file. It gets copied as any other
copy tool would do.
Saturated Hardlinks
The files E and F are hardlinked together. In LSE
terms they are called Saturated Hardlinks, because the reference count,
which is here 2, matches the number of occurrences below 'Folder 1', which is here
2.
In General: A hardlink is called Saturated with respect to a folder F,
if the number of occurrences below the folder F matches the reference count.
Saturated Hardlinks can be copied completely via Smart Copy.
Unsaturated Hardlinks
The File A, C, D are hardlinked together. In LSE terms
they are called Unsaturated Hardlinks, because the reference count,
which is here 3, does not match the number of occurrences below 'Folder 1', which
is here 2. Only C and D are below Folder 1.
In General: A hardlink is called Unsaturated with respect to a folder F,
if the number of occurrences below the folder F is smaller than the reference
count.
Unsaturated Hardlinks can only be partially copied by Smart Copy. In the above example
C and D are hardlinked together in the destination location, but the hardlink to
A is broken. This means that the reference count of C and D is 2 with the destination
location.
With junctions or symbolic link directories
the default behaviour
during smartcopy is as follows:
By closely looking at the above picture one can find three different types of folders/junctions:
Normal Folders
The folder 'Folder 3' is a normal folder. It gets copied
with its content as any other copy tool would do.
Inner Junctions
Symlinks
The folder 'Inner Junction/Symlink' is targeted at 'Inner
Junction/Symlink Target'. In LSE terms this kind of folder is called
Inner Junction/Symlink
, because its target points to a folder, which is below
the common anchor 'Folder 1'.
Inner Junctions/Symlink are restored properly via Smart Copy in the destination
location.
Outer Junctions
Symlinks
The folder 'Outer Junction/Symlink' is targeted at the
folder 'Outer Junction/Symlink Target'. In LSE terms this kind of folder
is called Outer Junction/Symlink, because its target points to a folder,
which is in parallel and thus outside the anchor 'Folder 1'.
Windows7/8/10 and Windows Vista support Symbolic Links, which behave as follows during
Smart Copy:
By closely looking at the above picture one can find three different types of files/symbolic
links:
Normal Files
The file A is a normal file. It gets copied as any other
copy tool would do.
Inner Symbolic
Links
The symbolic link 'Inner Symlink' is targeted at 'Inner
Symlink Target'. In LSE terms this kind of symbolic link is called
Inner
Symlink
, because its target points to a file, which is below the common anchor
'Folder 1'.
Inner Symlink are restored properly via Smart Copy at the destination location.
Outer Symbolic
Links
The symlink 'Outer Symlink' is targeted at the folder
'Outer Symlink Target'. In LSE terms this kind of symbolic link is called
Outer Symlink, because its target points to a file, which is in parallel
and thus outside the anchor 'Folder 1'.
Smart Copies are created in the same way as Junctions, select a folder, click the
Action button, choose Pick Link Source from the action menu...
...navigate to the destination folder, press the action button, open the
Drop As
...
submenu and select Smart Copy:
Smart Copy is a must if e.g.. the whole content of a hard disk, which has lots of
hardlinks/junctions/symbolic links, should be copied to another hard disk. During
the Smart Copy operation empty folders get copied too and the date/time stamps of
folders/junctions/symbolic links are also restored at the corresponding destination
locations.
Because Smart Copy creates inner hardlinks/junctions/symbolic links, this feature
is only available on NTFS volumes.
If Smart Copy takes longer than 250msec a progressbar shows the status of the smart
copy operation.
Smart Copy also processes all available alternative NTFS streams of a file.
If items are already available in the destination, Smart Copy only copies when the
Files/Symbolic/Junctions/MountPoints are newer than the already existing items.
When restoring Symbolic links under Windows7/8/10 and Windows Vista, LSE forks its helper
LSEUacHelper.exe to forwards this operation to it, because the creation of symbolic links
needs elevation, and thus brings up the famous UAC dialog.
LSE only issues its helper LSEUacHelper.exe if a symlink is among/below the selected
folders, so it saves you from one UAC prompt if you don't have symlinks among your
selection.
Smart Copy by default creates relative symbolic
links during the Smart Copy operation.
Command Line The Smart Copy functionality is also available via command line from
ln.exe
via the --copy command line switch.
Crop breaks links to Outer Junctions/Symlink directories
in the destination.
Crop also applies to Outer Symlink Files.
In the above example Folder1 is copied to Destination/Folder1, but
Outer Junction/Symlink is not available in the destination, because
Folder1/Outer
Junction/Symlink
pointed to Folder0/Outer Junction/Symlink Target,
which is not below Folder1.
The objective behind cropping Outer Junctions/Symlink Directories is to get a pure
copy during Smart Copy, Smart Mirror, Delorean Copy and Clone without connections
to the source.
Enabling Crop for Outer Junction/Symbolic Links Crop can be selected via the configuration tool.
Unroll
Unroll follows Outer Junctions/Symlink Directories
and rebuilds the content of Outer Junctions/Symlink Directories inside the hierarchy
at the destination location.
Unroll also applies to Outer Symlink Files, which means, that unroll causes
the target of Outer Symlink Files to be copied to the destination location.
In the above example Folder1 is copied to Destination/Folder1, and
Outer Junction/Symlink and all the files/directories below
Outer Junction/Symlink
Target
are copied to the folder Outer Junction/Symlink in the destination.
The objective behind unrolling Outer Junctions/Symlink Directories is to get everything
with which the source is connected and rebuild it as seperate copy in the destination.
It resembles the 'hair of the elephant' pattern: Pull on a hair of an elephant,
and get the whole elephant.
Unroll is the default behaviour for Smart Copy, Smart Mirror, Delorean Copy
and Clone.
Advanced thoughts on Unrolling
The picture above was just the simplest case, because Unroll does much more
when it encounters complex situations. Think of a outer junctions/symbolic links,
which itself contains junctions/symbolic links, which are inner with respect to
the first outer junction symbolic link:
In the above example Folder1 is copied to Destination/Folder1, and
Outer Junction/Symlink and is unrolled as expected, but since Junction/Symlink
is a inner junction with respect to Outer Junction/Symlink Target, the junction/symlink
relation is restored in the destination.
This kind of nesting can be much more complex:
In the above example Folder1 is copied to Destination/Folder1, and
Outer Junction/Symlink and is unrolled as expected, but then it starts to
get fascinating, because we have two levels of outer junctions/symlinks which all
have respective inner junctions/symlinks, and which are restored properly. Once
you digged yourself through the above picture, you got it. It is not simple I know,
but it is necessary to properly unroll.
And complexity increases if symbolic link files are within unrolled outer
junctions/symbolic links:
In the above example Folder1 is copied to Destination/Folder1, and
Outer Junction/Symlink and is unrolled as expected, but it contains
Inner
Outer Symlink
which points to Inner Outer Symlink Target and this is
a inner junction/symbolic link with respect to Outer Junction/Symlink Target
But worth mentioning is the Symbolic Link Outer Symlink, which would be a
definitive outer symbolic link, but since its targets parent-directory
Outer Junction/Symlink
Target
is unrolled, Outer Symlink becomes an inner symbolic link with
respect to Folder1.
File1 Symlink is also a outer symbolic link, but its target parent-directory
Folder2 is not that lucky to get unrolled, so in the destination File1 Symlink
is not a symbolic link any more, but a copy of the symbolic links' target.
Nested Reparse Points are also an interesting use case, which the algorithm has to tackle with:
In the above example Folder1 is copied to Destination, and
Junction/Symlink F0 and is unrolled as expected, but it contains inner
nested reparse points. Nested means Reparse point pointing to Reparse Points
The Unroll functionality also opens up the possibility to have circular Junction/Symbolic
Link relations among a set of copied items:
In the above example Folder1 is copied via the --unroll option to Destination/Folder1.
Smart Copy/Smart Mirror and Delorean Copy operations can deal with the above shown
circularities and break circularities by not following the affected Junction/Symbolic
Link.
Junctions/Symbolic Links can also point to FAT drives or other NTFS drives requiring
as a prerequisite unique Disk-IDs on all disks, which are chained together via Junctions/Symbolic
links:
Hardlink siblings are found by matching the per NTFS volume uniqe file-id, but if
more volumes are chained together it might happen that the same file-ids can be
found on two different NTFS volumes. To address this all operations use the disk-id
and the file-id to match hardlink siblings.
Furthermore it is not allowed to have the disk-id 0xffff-ffff, because the algorithms
use this as internal indicator of a FAT drive.
The Unroll option also allows to point multpile junctions to the same target location,
which causes the algorithms to traverse the same items many times:
At the first glance multiple traversation of items looks simple, but for files this
means that multiple traversed files are the same in the destination and are hardlinked
together. So don't be confused when you see hardlinks, which have never ever been
there before.
Copying Junction/Symbolic Links from mapped network drives also needs extra care, because
junctions on the remote machine relate with path references only valid on the remote machine
to each other:
The example in the above picture shows such a situation
X:\Src\Foo\Junction/Symlink is a junction on a Remote Machine, which points to X:\Src\Foo\Folder.
It is a valid Junction.
X:\Src\Foo is sharded via \\RemoteMachine\MyShare, which still is no problem.
\\RemoteMachine\MyShare mapped to T:\ on a local machine is fine, but the Junction T:\Junction/Symlink,
if asked for its target, will still return X:\Src\Foo\Folder even on the Local Machine. One could expect
that the target is T:\Folder, but it is not for Junctions.
When SmartCopy/Mirror/Delorean comes across such a situation, it translates the Junction correctly when
it is copied onto the Local Machines drive Y:\, so that the final Junction target points correctly to
Y:\Dest\Bar\Folder
Splice reconnects Outer Junctions/Symlink directories
in the destination to their original targets.
In the above example Folder1 is copied to Destination/Folder1, and
Outer Junction/Symlink is available in the destination as junction, which
points to the original location Outer Junction/Symlink Target.
The objective behind splicing Outer Junctions/Symlink Directories to its original
location is to get a copy during smartcopy, but to reuse Outer Junctions/Symlink
Directories source locations.
The Splice functionality is also useful, when mountpoints should be copied. Mountpoints are very similar
to Junctions, but point to a path always starting with \\?\VolumeGuid{}.
Multpiple Source Locations can be specified for SmartCopy, Clone, and
Delorean Copy. If there are junctions/symlinks between these source locations, they are handled as
inner junctions/symbolic links, because all source locations are dealt like a common root.
In the above example Location1 and Location2 are copied to Destination.
Location2/Junction20 is treated as inner junctions to Location1/Folder10 in the source,
and that's why Destination/Junction20 points to Destination/Folder10 in the Destination.
The objective behind this is to treat all junctions/symlinks as inner junctions/symlins as long as
they are in the set of source folders.
With LinkShell Extension this works as follows:
In the above example all content from Location 1 and Location 2 and pskill.exe are selected. Possible
junctions/symbolic links in Location 1 pointing to Location 2 or vice versa are treated as inner
junctions/symbolic links, because all selection is treated as a common root.
Smart Move enables folders with junctions and symbolic links beneath to be renamed, and the
junctions and symbolic links' targets are updated below that folder. Without Smart Move
renaming of such folders would end in dead junctions and symbolic links.
With junctions or symbolic link directories it behaves as follows:
By closely looking at the above picture one can find three
different types of folders/junctions:
Normal Folders
The folder 'Folder 3' is a normal folder.
It gets moved with its content straight forward.
Inner Junctions Symlinks
The folder 'Inner Junction/Symlink' is targeted at 'Inner Junction/Symlink Target'.
In LSE terms this kind of folder is called Inner Junction/Symlink, because its target
points to a folder, which is below the common anchor 'Folder 1'.
Inner Junctions/Symlink are updated properly via Smart Move in the destination location.
Outer Junctions Symlinks
The folder 'Outer Junction/Symlink' is targeted at the folder 'Outer Junction/Symlink Target'.
In LSE terms this kind of folder is called Outer Junction/Symlink, because its target
points to a folder, which is in parallel and thus outside the anchor 'Folder 1'.
Outer Junctions/Symlinks are not touched by Smart Move and thus stay connected to their respective target.
Please note that this is different to Smart Copy, which has
3 different
ways
to deal with Outer Junctions/Symbolic Links.
The Smart Move functionality is integrated into Explorer seamlessly, so that you don't have to
do anything special. Simply drag a folder in explorer to its destination location, or e.g. press F2
in Explorer to rename a directory and LSE will intercept this operation under the hood, takes care of
junctions or symbolic links, and will update them.
Intercepting move and rename operation means, that LSE takes over control before rename/move, and recursivley
searches the selected folder for junctions or symbolic links. But searching large amounts of files and
folders takes time, so LSE will show a progress bar when searching takes longer than 250msec.
With Vista & Windows7/8/10 LSE calls its UAC helper LSEUacHelper.exe if it has to
update symbolic links, so don't be afraid if you get a UAC prompt during moving of folders.
Smart Move creates
relative
symbolic links during the Smart Move operation.
Enabling/Disabling Smart Move
Smart Move can be switched on/off via the configuration tool
Command Line
The Smart Move functionality is also available via command line from
ln.exe
via the --move command line switch.
Clones are copies of a folder tree from a source location recreated at the destination location, however the
files within the new folder tree are Hardlinks or Symbolic Links to the respective files in the source folder tree.
A folder tree might also contain Junctions or
Symbolic Links. The clone process recreates inner junction/symbolic
links at the destination location very similar as Smart Copy does.
With Windows Vista and Windows7/8/10 this cloning process is also available with Symbolic Links instead of Hardlinks.
Clones are created in the same way as e.g Junctions. Select a folder,
click the Action button, choose Pick Link Source from the action menu...
...navigate to the destination folder, press the action button, open
the Drop As ... submenu and select HardLink Clone:
... or with Windows Vista or Windows7/8/10 choose
Symbolic Link Clone to create clones of existing tree structures.
HardLink and Symbolic Link Clones can also be created via Drag and Drop, select a folder and drag
with the action button depressed to a destination folder. When the action button
is released open the Drop Here... submenu and select HardLink Clone
or with Windows Vista and Windows7/8/10 Symbolic Link Clone:
HardLink or Symbolic Link Clones are useful if you need to replicate
a folder tree at a different location. The disk space required is minimal because
the new structure consists entirely of NTFS directory entries with no real amount
of actual data storage.
If both files and
folders are selected as Source Links and dropped as a
HardLink Clone then the selected files are dropped
as Hardlinks alongside the HardLink Clones.
Because Clones use Hardlinks or Symbolic Links, they are only available within an NTFS volume.
Hardlink Cloning can not replicate the folder structure from one disk volume to a
different volume, because Hardlinks are limited to operation on a single volume.
Symbolic Link Clones can be used to create volume spanning Clones, but only on Vista or Windows7/8/10
When creating Clones under Windows7/8/10 and Windows Vista, LSE forks its
helper LSEUacHelper.exe to forwards this operation to it, if the folder tree
contains symbolic links, because the creation of
symbolic links needs elevation, and thus brings up the
famous UAC dialog.
LSE only issues its helper LSEUacHelper.exe if a symlink is among/below the selected
folders, so it saves you from one UAC prompt if you don't have symlinks among your selection.
Command Line
The Clone functionality via Hardlinks or Symbolic Links is also available via
command line from
ln.exe
via the --recursive command line switch.
Smart Mirror is very similar to Smart Copy
and not only copies but synchronises the folder Source to Destination:
Smart Mirror copies if the timestamp of items in the Destination is different from the Source.
Delete files not anymore available in Source from Destination.
Smart Mirror takes care of Hardlink Relations, Restores Inner Junctions or Inner Symbolic links or when
issued unrolls or splices Outer Junctions or Outer Symbolic Links.
Smart Mirror is created in the same way as e.g Junctions. Select a folder,
click the Action button, choose Pick Link Source from the action menu...
...navigate to the destination folder, press the action button, open
the Drop As ... submenu and select Smart Mirror:
Smart Mirror is a little bit different with respect to Auto Rename, because
it expects a already existing folder in the destination location, which has the same name as the
source folder, so that it can do the mirror.
DeLorean Copy is a way of creating incremental backups
by using a combination of hardlink clone and Smart Copy.
The following picture gives an overview what DeLorean Copy is about
In general a DeLorean Copy has 3 principals: Source(t), InitialBackup and Backup(n).
Phase 1: Intial SmartCopy
The folder Source(t) is initially copied to
InitialBackup
. This is shown by the blue arrow.
Changes
happen
During this phase the files under source change, and
Source(t) becomes Source(t+1).
Phase 2: Hardlink Clone
The folder InitialBackup is Hardlink Cloned to
Backup1, which ties InitialBackup and Backup1. This is shown
by the red arrow.
Phase 3: Mirror
Mirror the folder Source to Backup1. This
is shown by the green arrow:
Keep unchanged files as hardllinks to InitialBackup.
Delete files not anymore in Source(t+1) from Backup1.
Copy different files from Source(t+1) to Backup1.
With completion of this first round Backup1 contains the first lean and mean
copy of Source only consisting of either hardlinks to InitialBackup,
or of copied files if there was the need to copy them over from Source(t+1)
because they were newer under Source(t+1).
The point is that all files in Backup1 are transparently accessible, but
really little space is used, because not all files in the Source(t+1) changed,
so that there was only the need to effectively copy over a few files from Source(t+1)
to Backup1.
This can be repeated on and on. The second round would be using Source, Backup1 and Backup2 for DeLorean Copy:
Changes
happen
During this phase the files under source change, and
Source(t+1) becomes Source(t+2).
Phase 2: Hardlink Clone
The folder Backup1 is Hardlink Cloned to Backup2,
which ties Backup1 and Backup2. This is shown by the red arrow.
Phase 3: Mirror
Mirror the folder Source(t+2) to Backup2.
This is shown by the green arrow:
Keep unchanged files as hardllinks to Backup1.
Delete files not anymore in Source(t+2) from Backup2.
Copy newer files from Source(t+2) to Backup2.
DeLorean Copies are created in the same way as e.g Junctions. Select a folder,
click the Action button, choose Pick Link Source from the action menu...
...navigate to the destination folder, press the action button, open the Drop As...
submenu and select DeLorean Copy:
If a DeLorean Copy was dropped the first time onto a directory, the operations, which are described under
phase 1 in the above descriptions, namely a Smart Copy, is performed. Link Shell Extension automatically
generated the folder name for the destination by appending a timestamp.
Any successive drop of a directory onto the a destination directory initates Phase 2 and Phase 3 from the
above description, namley it does the Hardlink Clone from the former backup onto the current backup and
furthermore does mirror the source onto the current backup.
A directory holding many copies may look like this.
Limitations
It is little known, but NTFS has a limit to create a maximum of 1023 hardlinks to one file. For
DeLorean Copy this means that it will display an error message if this limit is exceeded, because
exceeding this limit means loss of data among the most recent backup sets:
The reason for exceeding this limit could either be, that there have been more than 1023 backup sets
but no hardlinks within the Source, or there are hardlinks within the Source and less than 1023
backup sets.
The DeLorean Copy submenue will not appear if more than one folders are selected as source.
DeLorean Copy is long path safe which means it can handle more than 256 characters in pathes. This is
important, because placing a copy with quite long path, but still below 256 characters path length,
to destination locations might result in combined path length greater than 256 character. In such a situation
no data loss must happen, which Delorean copy guaranties with beeing 'long path safe'.
Please make sure that Explorer can not show you the result of such a copy, but the files are there.
Alternative explorers like SpeedCommander can handle this.
Command Line
DeLorean Copy functionality is also available via
ln.exe
Backup mode enables LSE to also copy ACLs and Encrypted Files from all directories, even the ones
without access for the current users.
With Windows7/8/10 LSE always forks its helper process LSEUacHelper.exe, and thus raises the
UAC prompt for elevation and password verification.
With WindowsXP LSE only goes into Backup Mode, when the current user has the necessary
privileges.
It applies to SmartCopy, SmartMirror, SmartClone, Delorean Copy, SmartMove
and Replacement Junction/Symbolic Link/Mountpoint.
LSE.exe thus copies
Alternative Streams on files and folders
EA Records on files and folders (rarely used)
Reparse Info
File Attributes
Timestamps: Creation Time, Last Access Time, Last Write Time
Sparse Files and Alternative Sparse Streams
Encrypted files
ACLs
Backup Mode is disabled by default, and can be turned on via the LSE configuration tool.
To perform backup operations a user must hold the SE_BACKUP_NAME and SE_RESTORE_NAME privileges.
An out of the box Wndows configuration assigns the Backup-Operator and Administrator group these privileges, but
additionally the above privileges can be assigned individually to certain users or groups.
Assigning privileges can be accomplished
By gpedit.msc
and navigating to
"Computer Configuration" ->"Windows settings" -> "Security Settings"
-> "Local Policies" -> "User Rights Assignments" -> "Backup files and directories"
"Computer Configuration" ->"Windows settings" -> "Security Settings"
-> "Local Policies" -> "User Rights Assignments" -> "Restore files and directories"
Without gpedit.msc
Download PolsEdit and add users or groups, who should be able to run
backups, to the SE_BACKUP_NAME and SE_RESTORE_NAME privileges.
Volume Mountpoints are a feature of NTFS version 5.0, which provides functionality to
map complete local volumes onto arbitrary disk locations. Volume Mountpoints
were not supported in NTFS Version 4.0
Volume Mountpoints
are created in the same way as Hardlinks, except that the
Source Link is a volume rather than a file. Select a
local volume, click the right mouse button, choose
Pick Link
Source
from the action menu, navigate to the
destination folder, click the action button, open the
submenu Drop As ... and select
Volume Mountpoint:
Volume Mountpoints can also be
created via Drag and Drop when the selected local volume is
dragged with the action button pressed to a destination
folder; when the right mouse button is released, select the
Drop Here ... submenu and then
Volume Mountpoint.
Mount Points can be
deleted by using the Unmount Volume command from Explorer as
usual.
To show the origin of a Volume Mountpoint, the reference column of a
Volume MountPoint shows the volume which is mounted onto the selected path.
Make sure that only local volumes can be mounted but not mapped network drives.
Vista & Windows7/8/10: With Vista & Windows7/8/10 the creation and deletion of Volume Mountpoints is bound to
successful elevation, which means that the famous UAC dialog
must be acknowledged.
@Microsoft: Why is it not possible with Windows7/8/10 & Vista to create a
Volume Mountpoint under e.g. 'c:\Program Files'. The return value on the
CreateMountPoint() call is ERROR_INVALID_PARAMETER, which is always the
'Error I don't know what to do' thrown by Windows. Please fix this!
As described in the
backgrounders section within
the “default” data stream of all data objects
NTFS maintains a reference count how many NTFS directory
entries refer to object. In most scenarios each entry will
refer a different folder, although it is possible to have
multiple links to the same data object in the one folder,
providing they have folder unique names
To show the reference
counts, a column can be enabled in Explorers right pane by
action clicking the Titles row of the details
view.
After enabling the
reference column the reference count is shown for each
file. This feature is only available in Windows 2000 and
XP, it is not supported in Windows NT4.
Vista & Windows7/8/10: The column, which shows the reference
count and the origin of the junction is not available, because the way Vista and Windows7/8/10 handles
user defined columns has been completely revamped by Microsoft and all applications working with
so called ColumnHandlers will not work. Microsoft did such a good job in changing interfaces, so
that it is impossible to revive this feature in Windows7/8/10. Sorry.
Link Shell Extension also supports
so called Explorer Property Sheets, which means that if a
file or directory property in explorer is opened, Link
Shell Extension adds its own tab to show the properties of
a hardlink, junction, volume mountpoint or symbolic link.
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.
Explore
For junctions, volume mountpoints or symbolic links this dialog also shows
a 'Explore Target' button, which opens an explorer in the specified directory.
Edit
For Junctions, Symbolic Links or Mountpoints the target field can be edited, and after either pressing the Apply button
or leaving the Link Property dialog with ok, the changes are applied to the Junction, Symbolic Link or Mountpoint.
If the Backup Mode is enabled, the ACL of the edited Junction, Symbolic Link or Mountpoint
is preserved.
With Windows Vista and Windows7/8/10 NTFS introduces a
new type of link, the Symbolic Link. LSE supports the creation of symbolic links
under Windows Vista and Windows7/8/10.
Creating a
Symbolic
Link
is essentially the same as the other Link creation
processes. Action click on the selected file(s) and select
Pick Link Source(s) from the action menu.
Under Vista/W7 when the
destination folder is action clicked the menu contains a
Drop As ... submenu, to create a Symbolic Link
select SymbolicLink from the submenu. Unlike Hardlinks
Symbolic Links can span storage volumes.
If both files and
folders are selected as the Source Links and dropped as a
Symbolic Link Clone then the selected files are
dropped as Symbolic Links alongside newly created
Symbolic Link
Clone
folders.
Symbolic Links can also be
created between directories.
a fully qualified path starting at the root of a drive, e.g e:\data\cpp\myfile.txt
or can be be specified relativeley, e.g ..\..\data\cpp\myfile.txt
LSE by default tries to create relative target path names for symbolic links as long as
this is possible, e.g the file and its target are on the same logical drive.
Having relative symbolic link targets is much smarter especially when the target of links
is in the same directory.
If a symbolic link and its target are on different drives, LSE uses absolute pathnames.
The configuration tool can switch Link Shell Extension in either
relative or absolute mode.
Overlay Icons for Symbolic Links
To help distinguish Symbolic Links from normal files/directories, an overlay icon is implemented
on symbolic links that shows a light green arrow icon under the folder.
Overlay icons for Symbolic Links can also be customized.
@Microsoft: Symbolic links without elevation: Lets see if this paragraph
is read by someone. I don't know if it is a bug or a feature, but one
can create symbolic links without elevation, if you create a hardlink
from a symbolic link. That sounds weird, but it works. And by a closer
look at this stuff, it can be seen, that LSE really uses CreateHardlink()
and a symbolic link is created. MS guys! Your opinion?
@Microsoft: Symbolic can span network drives as long as the target is a
drive letter mapped drive, but it fails for UNC names in symbolic link target with
error ERROR_LOGON_FAILURE(1326), even if the network is connected properly.
With Vista and Windows7/8/10 it is possible to enumerate
all hardlink siblings to a file in constant time. Simply select a hardlinked file and select
Properties from the right click action menu:
Unfortunately this feature is currently only available with Vista
since the Win32 API calls to enumerate hardlinks are not available with XP or W2K.
Under XP reading and processing the unique file ID of all filenames on a disk
is necessary to gather the same information. Since this operation is timeconsuming,
the siblings of a hardlinked file are not shown immediately after opening
the properties tab, but the 'Enumerate Siblings' button must be pressed.
Enumeration of all siblings under XP can take time, because in the worst case all
files contained on a logical volume must be at least opened for the filename.
The Hardlink Enumeration functionality is also available via
command line from
ln.exe
via the --enum or
the --list command line switch.
One of the major Windows7/8/10 changes was the so called
User Account Control (UAC)
. Due to UAC some API calls need elevation to administrative
level, and this elevation must be acknowledged via the below shown dialog box. Unfortunately,
and I still can't believe this, the API call CreateSymbolicLink is a call, which
needs elevation, and thus causes this annoying dialog box come up every time a symbolic
link is created.
So if you see the below box, and the program asking for elevation is LSEUacHelper.exe,
it is Link Shell Extensions contribution to UAC and you must acknowledge it to get
Symbolic Links created.
UAC will be the reason, that many applications simply
either will not work, or are not useable with Windows7/8/10. They are not useable, because
privileged API calls and non privileged API calls are mixed in the code, and first
need to be separated by architectural means into an separate .exe, which gets elevated,
and an .exe for the rest of the coding.
Many applications will simply fail, because calls like CreateProcess(), which are
very common, do not work, if the process started with it needs elevation. Well the
story goes on and on, and Link Shell Extension is a very small application, but
to walk the learning curve was a hard way, especially because the documentation
was rather difficult to get.
I guess the main protection of UAC is that many small legacy apps are impossible
to rewrite for Windows7/8/10, and they simply can not be used with Windows7/8/10 efficiently.
One way to come around the UAC prompt for the creation of Symbolic Links is to globally allow users to create Symbolic
Links by changing the policy.
With gpedit.msc
Start gpedit.msc from the command line and grant/revoke specific users the permissions: Under
"Computer Configuration" ->"Windows settings" -> "Security Settings" -> "Local Policies" -> "User Rights Assignments" -> "Create Symbolic Links".
Without gpedit.msc
Download PolsEdit and add users to SE_CREATE_SYMBOLIC_LINK_NAME.
Linkshell Extension can deal with the above granting of privileges, and if the Symblic Link Privilege is available avoids the UAC prompt.
Developer mode in Windows10
Another way to come around the UAC prompt would be to
enable the developer mode,
which is available since Windows10/14972.
It is little known, but the SMB networking protocol supports operations to
create remote Hardlinks, Junctions and Symbolic Links within SMB mapped
network NTFS drives.
This feature is used by Link Shell Extension, to enable the creation of
so called Remote Hardlinks, Remote Junctions, or Remote Symbolic Links. e.g.
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 SMB1.0 also reports the reference count for Hardlinks and
the junction origin for Junctions, which enables Link Shell Extension
to show the properties dialog for remote files. Currently the reference
count of a hardlink is reported via SMB1.0 in 90% correctly, so please
be aware of this restriction.
@Microsoft: Why does this happen in 90%? I have scanned my code
in the meantime many times, and it is obvious, that the same call
sometimes succeeds and sometimes not. Why??? If you wanna hunt
down a bug in your code, please contact me!
LSE supports both, mapped network drives and UNC paths.
Mapped but not available network drives can in general be the reason
for sloppy explorer startup performance. Delays of a few seconds can
be experienced if explorer has to check all drive mappings, especially
the ones which are not available. This gets worse, if LSE also checks the status
of all drives.
To workaround this caveat the Remote Capabilities of Link Shell Extension
can be switched on/off via the configuration tool.
Remote Hardlinks and the SMB version
There are differnet SMB Version implemented in different Windows versions which means different
behaviour for hardlinks:
SMB1.0: Windows XP, Windows2000 ...
SMB2.0: Windows Vista ...
SMB2.1: Windows7/8, Windows Server 2008 R2 ...
SMB3.0: Windows10, Windows Server 2012 R2 ...
All of those version support the creation of hardlinks remotely, but since SMB2.0 one
can not find out if a file on a remote drive is a hardlink or not.
This means, that e.g if you connect with your Windows XP machine to a SMB2.1 drive,
which is provided by a Windows7/8/10 machine, you will not be able to see overlay icons
for hardlinked files, but you will be able to create them remotley.
@Microsoft: Is this implementation since SMB2.0 a bug or a feature?
LSE supports removable media, which have been formatted with NTFS, to create
all kind of features it does for fixed drives too. The only limitation
is that it intentionally won't work on removable media if they
are mounted to drive A: or B:. The reason is that A: or B: are commonly used for floppy drives.
With removable media formatted to NTFS there is the slight chance that LSE reports
'Access denied' problems, when creating hardlinks or junctions. This is due to
file object permissions on the removable NTFS drive, which have been created with a different
computer on that removable media, thus causing this 'Access denied' messages. The solution
here is to change the permission on that removable media as Administrator.
The Win32 API supports pathnames up to 256 characters,
thus limiting all applications to that length for pathnames.
On the other hand NTFS supports pathnames with up to 32767 characters, so one might
have already experienced pathnames, which are longer than 256 characters. To deal
with that, LSE can handle Very Long Path up to 32767 characters with all
operations.
With the subst.exe command one can create driveletters, which point to certain path on a NTFS volume. This means that two
different driveletters in the end might resolve to locations on the same NTFS volume.
Link Shell Extension checks these situations when it comes to allow the creation of hardlinks, and as a consequence allows
the creation of hardlinks among different logical drives if they resolve to the same NTFS volume.
Technically it seems that NTFS5 even shipped with WindowsXP has always supported symbolic links, but the functionality was
not available for user mode applications, and even not for the upper layers of ntfs.sys
BUT: There are filter drivers available from Masatoshi Kimura for even WindowsXP, which enable symbolic links
under XP. These drivers can be downloaded from his home page for 64 bit and for
32 bit. The
sources
are also available.
Installation of these drivers is also quite simple.
Unpack the archive for your plattform,
Open a command shell with administrator access privileges on a directory,
containing both, senable.exe and symlink.sys, to run following commands:
senable.exe install
copies the driver symlink.sys to %systemroot%\system32\drivers, registers it at
HKLM\SYSTEM\CurrentControlSet\Services\SymLink and starts it.
senable.exe delete
deletes the driver symlink.sys from %systemroot%\system32\drivers and registry,
but nothing more. Once copied to %systemroot%\system32\drivers and registered, it
still needs to be activated by seneable.exe on each Windows start. To unload the
driver after deletion you need to reboot Windows, logoff is not enough.
To start the symbolic link driver automatically, change the registry value HKLM\SYSTEM\CurrentControlSet\Services\SymLink\Start from 2 (automatic) to 0 (boot).
From now on, symlinks automatically become working after each Windows start, even if directly logged into your limited account.
Link Shell Extension enables its complete symbolic link functionality under XP as soon as it finds
this driver loaded. And, sensation(!): There is no UAC prompt necessary under XP for creating symbolic links ;-))
Furthermore there are reports from users who tried out the driver and LSE also under Windows2000, and everything
works fine.
With Windows Server 2012 Microsoft introduced the
ReFS
filesystem, which is the designated successor to NTFS. But the first
implementation of ReFS can do nice things, but lacks a few important features from NTFS like the Hardlink support.
Link Shell Extension supports ReFS so that one can create Symbolic Links, Mountpoints, Junctions on ReFS volumes.
But it will throw an error message if a hardlink is about to be created on a ReFS volume. So what are the impacts on
Link Shell Extension in detail:
ReFS drives as the destination of Delorean Copies will for sure fail, at least when creating the second backup in a Delorean set.
Since ReFS is expected to support the full set of NTFS functionality in a later release, Link Shell Extension has no
checks implemented to tackle with the above constraints.
There are a lot of filesystems out by third party vendors nowadays, which support hardlinks, symlinks...
In order to provide the LSE functionality on that drives, the supported filesystems can be configured:
Add your favourite filesystem name in a comma seperated list to
Changes to the known filesystems from the above registry key take efect after an explorer.exe restart.
If you don't know the name of the filesystem you might determine this by issuing
ln.exe from a command prompt.
ln --probefs x:
By default Btrfs is configured as a known third party filesystem.
Configuring your favourite filesystem to be recognized by LSE is on your own risk. Basically LSE would do all operations
to the configured filesystems, which it does to NTFS. So make sure your filesystem supports the same primitives as NTFS does
otherwise certain operations will fail.
Link Shell Extension can be tweaked/configured to fit the different personal taste
in some aspects. To ease this, Link Shell Extension has a companion called LSEConfig,
which changes Link Shell Extension behaviour via a User Interface. Once started, LSEConfig will throw
the famous UAC UAC dialog, because Link Shell Extensions
settings are changed in the Windows registry.
Localisation
Link Shell Extension's UI and commands are available in a few languages.
You can choose from
English(default)
Chinese
Czech
French
German
Greek
Italian
Japanese
Korean
Polish
Portuguese Brazilian
Russian
Slovak
Spanish
Swedish
Turkish
Changing the UI Language of Link Shell Extension will need a restart of the explorer once
Apply or Ok is pressed.
Smart Move
It might be useful to totally switch off Smart Move,
if there are folders with really much folders.
This can be acchieved by ticking the Smart Move checkbox.
Logging
All output of a LSE operation like SmartCopy, SmartMirror, or Delorean Copy is logged to the file %TEMP%\LinkShellExtension.log
Remote Capabilities
It might be useful to totally switch off Remote Capabilities,
if there are lots of 'dead network drives' around.
This can be acchieved by ticking the Remote Capabilities checkbox.
Outer Junction/Symbolic Link Handling
Decide whether Outer Junctions should be handled as Crop,
be Unrolled, which is the default, or Spliced.
Symbolic Link Creation
By selecting either relative or absolute Link Shell Extension will
create the target of Symbolic Links respective.
Copy Mode
By checking the Backup Link Shell Extension will run in Backup Mode. On WindowsXP
this check box is grayed and its content set to unchecked, if the current user does not have sufficient privileges.
Link Shell Extension has built in overlay icons for junctions, hardlinks and symbolic links.
Since icons are subject to individual taste, the icon used by Link Shell Extension can
be specified.
Changing any settings related to overlay icons will ask for a restart of explorer
when Apply or Ok is pressed.
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.
Priority
Only one overlay icon can be shown with an icon, but many overlay handlers might apply
to provide the overlay icon. To sort this out each overlay handler can specify a priority
to explorer and explorer shows the overlay icon with highest priority.
High priority means lower number, with 0 as the highest priority
Custom Icon
By ticking the checkbox for custom icon the Browse... button gets enabled,
and an icon can be selected.
Keep in mind that custom icons are specific to each user.
General Windows Vista and Windows7/8/10 are a little bit special, because overlay icons for 256x256 must not
be in the lower left corner of the icon, and must not be already smaller to perfectly 'overlay'
an icon. 256x256 overlay icons must fill up the complete available icon, and also must not be resized.
Vista does that for you for 256x256 icons.
Or in other words Vista takes any 256x256 icon and resizes it to 92x92, moves it to the
left lower corner and overlays.
For all other resolutions smaller than 256x256, Vista works in the same way as XP, you have
to prepare an overlay icon in the lower left corner.
Furthermore Vista icons should not be saved 'compressed', because XP can not read compressed icons.
For my investigations the icon editor of choice capable of dealing with Vista icons was
RealWorld Icon Editor
Apply Changes
When you press OK or Apply on LSEConfigs dialog, settings will be taken over.
If changes were made to Link Shell Extensions language settings or
settings related to overlay icons, you will be asked to confirm a restart
of explorer.exe, so that your changes become effective. Restarting
explorer.exe means, that e.g. any copy operation or other pending operation
within explorer.exe is interrupted.
Hardlinks are a feature common to many
Unix based systems, but are not directly available with
NT4/W2K/WXP. It is a feature, which must be supported by
the file system of the operating system.
So what are
Hardlinks? It is common to think of a file as being an
association between a file name and a
data
object
. Using Windows Explorer, the file system can be
readily browsed, showing a 1:1 relationship between the
file name and the data object, but this 1:1
relationship does not hold for all file
systems.
Some file systems,
including UFS, XFS, and NTFS have a N:1 relationship
between file name and the data object, hence
there can be more than one directory entry for a
file.
So, how does one
create multiple entries for the same data object? In Unix
there is a command line utility ln, which is used to
create link entries for existing files, hence there are
many file names, or so called Hardlinks, for the one data
object.
For each HardLink
created, the file system increments a reference count
stored with the data object, i.e. it stores how many
file names refer to the data object, this counter is
maintained (by the file system) within the data object
itself. When a file name referencing a
data object
is
deleted, the data object’s reference
count is decremented by one. The data object itself
only gets deleted when the reference count is
decremented to zero.
The reference count is
the only way of determining whether there are multiple
file name references to a data object, and it
only informs of their number NOT there
whereabouts.
Junctions
are wormholes in the tree
structure of a directed graph. By browsing a Junction a
maybe far distant location in the file system is made
available. Modifying, Creating, Renaming and Deleting files
within a junction tree structure operates at the junction
target, i.e. if you delete a file in a Junction it is
deleted at the original location.
Symbolic Links are to files what
Junctions are to folders in that they are both transparent
and Symbolic. Transparency means that an application can
access them just as they would any other file, Symbolism
means that the data objects can reside on any available
volume, i.e. they are not limited to a single volume like
Hardlinks. Symbolic Links differ from Shortcuts in that
they offer a transparent pathway to the desired data
object, with a shortcut (.lnk), something has to read and
interpret the content of the shortcut file and then open
the file that it references (i.e. it is a two step
process). When an application uses a symlink it gains
immediate access to the data object referenced by the
symlink (i.e. it is a one step
process).
Supported platforms are NT4/W2K/WXP/W2K3/W2K3R2/W2K8/W2K8R2/W2K12/W2K12R2/WXP64/Vista/Vista/Windows7/8/10 in 32bit, 64bit or Itanium.
Hardlinks can only be made on NTFS volumes, under the
supported platforms.
Hardlinks can only be made within one NTFS volumes,
and can not span across NTFS volumes.
Junctions can not be created on NTFS volumes with NT4.
The Pick Link Source and Drop ...
choices are only visible, if it’s possible to
create Hardlinks/Junctions/Symbolic Links. E.G.: If you
select a file on a FAT drive and press the action button,
you wont see the Pick Link Source in the action
menu, because FAT file systems, don't support
Hardlinks/Junctions/Symbolic Links. 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 1023 hardlinks per file. This is
less known, but it is there.
Q: On Windows7/8/10, the Save As... box shows symlinks with the white "shortcut"
overlay, instead of the green symlink overlay.
A: This happens if the processes shown during installation of Link Shell Extension were not closed.
If you really run into this rare situation, a reboot will help.
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?
A: Once a file is deleted in Explorer it is moved into Recycle Bin, but not really deleted.
If you press Shift-Del for deleting a file instead of just pressing Del,
the file really gets deleted and the reference count is decremented.
Q: I could'nt make a successful hardlink for image or vector files - I mean, I was
able to *make* the hardlink copy, but when I modified one file it didnt affect the other.
I'm wondering do you know why this might be - could it be my otherwise quite normal computer (!)
or could it be something to do with the hard link proccess ?
A: You were able to make hardlinks successfully, but when you open a hardlinked file
for edit, it depends on the editor associated to the file if the file either gets
opened, changed, the original deleted, and the new one saved ( ==> link broken )
opened, changed, and saved back ( ==> link alive )
Q: When I deleted a directory, its junction point
is left behind
in an non-operational state.
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?
A: No sorry, Junctions are a one way relation, and if the targets disappears
the junction points to an orphaned destination.
Q: When I delete a symbolic link, which points to a zipped folder
by pressing DEL, later on when I want to empty the recycle bin, explorer denies
by showing me error message 0x80071128. What's wrong?
A: Unfortunatley this is a bug in Explorer, and it only happens to symbolic links
pointing to .zip files. The workaround is to move it manually out of recycle bin
rename it, and then delete it once more.
Q: I have created a symbolic link to an .exe and when I double
click on it, I get the following error message: The specified path does not exist. Check the path and try again.
A: Unfortunatley this is a bug in Explorer, and I don't have a clue how to come around this in explorer.
If you start the symlink to an .exe from a command prompt it works fine, and even third party
explorers like SpeedCommander can do this, but explorer seems to
have a limitation
Does anybody know the registry hack to enable this in explorer.exe? Drop me a line.
Q: I double click on a symlink in explorer, which e.g. points to an .xls, and the explorer asks me to
choose a program to open it.
A: With KB3039066 Microsoft changed the behaviour of symlinks. Uninstall it and it will work again. See also
Symbolic Link Type Changed
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.
There are currently fifteen slots allotted for icon overlays, some of which are reserved
by the system.
All is controlled by the alphabetical order of OverlayHandlers under
If the OverlayHandlers for LinkShellExtension somehow slipped to a slot greater 15 under 32bit Windows or
greater 11 with 64bit Windows, the LSE Overlay Icons won't show up.
To manually boost the priority of LSE OverlayIcons open the above registry location with regedit and rename
HardLinkMenu --> 0HardLinkMenu
IconOverlayHardLink --> 0IconOverlayHardLink
IconOverlaySymbolicLink --> 0IconOverlaySymbolicLink
and either restart the explorer or log-off and log-on again. The point here is to change the alphabetical order
by prepeding a 0.
With Windows 10, a 0 might not help but prepending a blank should do it. See below:
Q: The symbolic link overlay icons do not show up under Windows 10
A: See one FAQ above and raise the prio of IconOverlaySymbolicLink under
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers
by prepending two blanks.
IconOverlaySymbolicLink --> ' 'IconOverlaySymbolicLink
and either restart the explorer or log-off and log-on again. The point here is to change the alphabetical order
by prepeding blanks.
Q: I'm trying to store Dropbox files only on removable storage instead of the
internal 128gb of storage. My DropBox already contains lots of files. How do I accomplish redirecting
the dropbox folder to the removeable storage?
A:
Copy the whole dropbox folder from the internal storage under c:\users\[username]\dropbox
to e.g x:\data\dropbox
Rename the dropbox folder c:\users\[username]\dropbox to e.g c:\users\[username]\dropbox_org
Pick Link Source x:\data\dropbox
In c:\users\[username] use Drop as and select Symbolic Link for Windows7/8/10 or Junction for WindowsXP
If everything went fine finally delete c:\users\[username]\dropbox_org
Q: When I create Symbolic links they appear in Explorer as 0 bytes. I cannot remember if this is
expected or not?
A: The resulting Symbolic Links show as 0 bytes in explorer.exe, that's expected.
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.
A: The files in the backup sets of --delorean are hardlinked if they are the same. NTFS provides one set of timestamps and
attributes for all hardlink-siblings of a file, so if a file needs different attributes in a backup, it has to be copied.
Q: With WindowsXP I try to 'DEL' a directory, which is referenced via a junction or mountpoint. I get an 'Access Denied' message.
What's wrong?
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.
A: Unfortunatley this is an explorer problem, and LSE has no chance to intercept.
Broken symlinks/juncitons can be easily repaired by the replacement junction/symbolic link feature
Improved the progress estimation for the progressbar
Fixed crash in LSEConfig when it replaced the texts upon startup
Removed vcredist-vs2005 check from installer
[Internal] but important change from VS2005 (sic) to VS2017. Basically everything compiled smoothly except for the heap, thus...
[Internal] Removed the Rockall fast heap. 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.exe and LSE.
[Internal] Dropped Itanium configuration, since VS2017 does not support it anymore, and I am sure there is no Itanium hardware out in the wild anymore.
Junctions/Symbolic Links/Mountpoints ACLs are preserved when the target is changed either via
Replacement functions or editing from the Link Properties.
When working on mapped network drives via SMB or CFIS, as many NAS boxes do, LSE uses a more traditional enumeration mode and this will copy files ( which it did not in any case ).
Multiple locations can be selected and the location are treated as a common root with respect to hardlinks/junctions/symbolic links.
Nested junctions and symbolic links ( aka junctions on junction on junctions ... ) are now properly restored in any situation.
Smartmove had problems with relative symbolic links in rare situations.
The Properties dialog of an item offers an 'Explore Target'
button for Junctions, Mountpoints and Symbolic Links.
Added localization for Japanese. Thanks to Taka from Japan!
Under Windows7 auto rename behaves in the same way as Windows7/8/10 does for '- Copy'.
September 28th 2009
Version 3.1.6.0
With W2K the junction creation was broken.
Fixed a handle leak caused by enumerating hardlink siblings under non Vista/W2K8
Under Vista & W7 one can create junctions everywhere without elevation, but not in
e.g c:\Program Files. LSE is now aware of this and asks elevation for junction creation
when necessary.
With drives mapped via a Remote Dektop session, the whole explorer & remote desktop session hang, when
this drives was expanded in explorer, but only under W2K3 as terminal server.
Support for Windows7
Hardlink Sibling Enumeration now also works for XP, W2K NT4, but due
to OS contraints not that fast as with Windows7.
Under W2K it turned out, that CreateHardlink() from kernel32.dll with long pathnames (e.g. \\?\) was
broken.
Fixed a memory leak in serving as COM server.
October 4th 2008
Version 3.0.0.1
There is a new Smart Copy feature, which enables LSE
to copy whole folder structures and preserve the inner hardlink and junction structure.
Junctions can now be created targeting also Junctions.
June 21st 2008
Version 2.9.5.3
Hardlinks can be enumerated under Vista & Windows7.
Fixed a handle leak for HKCU\Software\LinkShellExtension.
Removeable media support didn't work, when remote capabilities were switched off.
May 1st 2008
Version 2.9.0.3
Already existing Junctions can be replaced by dragging a directory over it
Naming has been streamlined more towards 'Link Shell Extension'
If the maximum number 1023 of hardlinks for a file is exceeded, an error message is displayed. This applies
for hardlinks and hardlink clones.
The Vista & Windows7 junction overlay icon in 256x256 is in proper size.
Custom icons can be specified for Junction and Hardlink overlays
Version for Itanium available
Pick/Drop does not interfere with the creation of Hardlinks, Junctions or Symbolic Links via Drag and Drop.
It is now possible to pick a link, then drag another file via right mouse click to some location, drop it there
and afterwards drop the first, picked file
The property dialog of a Volume Mountpoint now displays the logical drive letter of the mounted drive
instead of the odd volume name.
Ongoing work towards localisation to East Asian languages.
Symbolic Links now can be created even if the filename contains UTF-16(Asian)characters.
LSE now also works for non Administrators under Vista & Windows7 (after they acknowledged the elevation dialog with the admin password for sure).
Symbolic Links for files or directories can now be created across volumes.
LSE now can also create Hardlinks from Shortcuts, which didn't work for ages.
The print name (the name some can see to the right of a junction, after issuing 'dir' in a command prompt) for Junctions under Vista & Windows7 is now correct.
Lots of usability fixes
During Installation under Vista64 Explorer automatically gets restarted.
The setup contains a check if the VS2005 SP1 Redistributable Package is installed.
The setup contains a check if the LSE version for the proper platform is going to be installed.
Vista & Windows7 compliant overlay icons for Hardlinks.
January 20th 2008
Version 2.8.0.6
Hardlinks show up with a small overlay icon. This icon will change for Vista compliancy, but at least it is here now.
Junctions have a Vista compliant overlay icon in many resolutions
Support of creation and deletion of
Volume Mountpoints. Unfortunately this does not work under Vista
LSE now prevents the creation of 'loops', when setting up a junction or hardlink clone
Hardlink 'cross drive drops' are now not possible anymore
Some bug fixes for NT4
Lots of usability fixes
October 16th 2007
Version 2.7.1.0
First fixes for the x64 world. Maybe more to come. Fixing x64 is top
priority since I have Q6600 myself now...
March 25th 2007
Version 2.7.0.1
Fixed a nasty bug, which caused HardlinkShellExt to slow down
explorer, when it was started. Also fixed the problem that it accessed
drive A:, when an explorer started.
PropertySheet on file and directory properties will show various info
with W2K/XP
Delete Junction is back, because sometimes, especially when deleting
junctions, which point to directories with big amount of data, the Copyhook Handler
does not act as expected. Until this phenomenon is solved, Delete Junction is back.
January 12th 2007
Version 2.6.0
Link Shell Extension is now robust with respect to
deleting junctions. Delete commands issued from explorer unlink
junctions, but do not delete its content.
Due to Junction-awareness of explorer the Delete Junction is gone from the
context menu
Support for Windows Vista & Windows7. Link Shell Extension is now capable of creating
Symbolic Links, but also has a few restrictions related to the Reference column
December 27th
2006
Version 2.5.1
released
Added localisation for Italian and Spanish to commands and messages. Thanks to
Nicola Guidotto and Diego Segobia for the translations.
December 6th
2006
Version 2.4.0
released
Added localisation for French and German to commands and messages
November 26th
2006
Version 2.3.0
released
Minor fixes in the installer/deinstaller
Introduced the hydraulics of multiple auto rename. If you drop links/junctions
in the same directory, now it behaves exactly as explorer and puts numbers
on the multiple instantiations of a file.
June 16th
2006
Version 2.2.2
released
BugFix. Link Shell Extension is now also able to create hardlinks
via Drag and Drop in root dirs of a drive.
Added
overlay icons for junctions, so that junction
visually pop into your eye.
February 27th
2006
Version 2.0
released
Revamped the
internal structure of ShellExt.
Introduced creation of Hardlink Clones.
Introduced submenu in the context menu, when
more than one entries would be added to context
menu to show the many dropping choices
Support for SymbolicLinks with 'Vista'.
Support for SymbolicLink Clones with
'Vista'.
Fixed crashes when dragging files, and using
'HardLink here'.
Fixed problem when showing up wrong menu, when
having folders disabled in the left explorer
pane.
Junctions display their origin in the reference
column.
A Pick Link operation can be cancelled
now.
The installer restarts explorer.exe to properly
add/remove the shell extension
Added an entry to Start Menu/Programs
Support for WindowsXP64.
November 26th
2005
Version 1.7
released
Added
the Delete Junction context menu,
when right mouse button is pressed on a
junction.
Fixed a handle leak in CreateJunction.
January 23rd
2002
Version 1.6
released
Added a
Columnhandler, so that the reference count of a
hardlinked file is shown in explorer. This feature
only works with W2K/WXP.
Deployment revamped so that the doc is now in
.html.
October 27th
2001
Version 1.5
released
Revamped
internal string handling to
Unicode.
Added junction support. Junctions are a feature
of NTFS5, which allows to hardlink two
directories.
Added a directory background handler. This
means, that after picking a hardlink it is possible
to press the right mouse button on the right
explorer pane and drop the
hardlinks/junctions/symbolic-links.
March 23rd
2001
Version 1.201
released
Fixed occurrence of 'Hardlink Here' if shortcuts are selected.
March 23rd
2001
Version 1.20
released
Added Drag and drop support
March 20th
2001
Version 1.10 released
Fixed the problem, that the help text was not displayed properly
Changed the installer to the lean and mean nullsoft installer.
Fixed the problem, that read-only files can not be hardlinked
Fixed the problem, that hardlinks in the root dir didn't work
Tested on W2K and HardlinkShellExt is W2K compliant
With Vista & Windows7 the column handler in explorer, providing the
reference count, does not work, since Microsoft deprecated
the interfaces with respect to this functionality.
License
This program is provided as is. See license.txt from this distribution for legal issues.
Link Shellextension uses tre as the regular expression machine. See the tre license.
This version contains the 64bit version of Link Shell Extension, but also
contains a 32bit version, which is installed in parallel to the 64bit version, to satisfy third party
filemanagers/explorers like total commander:
The Itanium version is not supported anymore, but the last VS2005 based version 3.8.7.2 is kept for legacy.
Please make sure that the necessary runtime .dlls are
installed on your system. This prerequisites package can be downloaded from Microsoft:
The version for Windows NT4 will be no more activley developed
on, and its functionality is frozen with version
Link Shell Extension 3.2.0.0 (1.13Mb), which basically has all
the important features.
The driver to enable even WindowsXP with
symbolic link functionality
is provided courtesy of Masatoshi Kimura. You can download the driver from his
homepage or from my site acting as a mirror.
French
Enabling Splice for Outer Junction/Symbolic Links
