Windows 10 Junction on UNC path



  • I had this setup years ago on a machine, and it has been working fine since.

    Machine died and was replaced.

    Now I cannot get anything to work like I used to do it.

    Goal: C:\Backup as a Junction or HardLink to \\server01\Share\Subfolder
    Reason: So Crashplan Pro can backup the files.

    This is a tertiary backup, so not critical, but it is a small subset for fastest restore in case of site fully dead, until the full VM's can be pulled back from B2.

    I can easily make a symlink mklink /D C:\Backup \\server01\Share\Subfolder. But Crashplan will not see the folder as it does not follow soft symlinks. It shows it as a 0 byte file.



  • When trying to use a /J I get this error.

    C:\>mklink /J C:\Backup \\server01\share\Backup
    Local volumes are required to complete the operation.
    


  • @JaredBusch said in Windows 10 Junciton on UNC path:

    When trying to use a /J I get this error.

    C:\>mklink /J C:\Backup \\server01\share\Backup
    Local volumes are required to complete the operation.
    

    Map \\server01\share\Backup to a Z: and then mklink /J C:\Backup Z:\Backup?



  • @black3dynamite said in Windows 10 Junction on UNC path:

    @JaredBusch said in Windows 10 Junciton on UNC path:

    When trying to use a /J I get this error.

    C:\>mklink /J C:\Backup \\server01\share\Backup
    Local volumes are required to complete the operation.
    

    Map \\server01\share\Backup to a Z: and then mklink /J C:\Backup Z:\Backup?

    Same
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    18e15627-a284-4fdc-a8a4-2c88693e0433-image.png



  • If you're trying to link a path to a drive, I think that subst might work or even psubst. I haven't used it in years.



  • @scotth said in Windows 10 Junction on UNC path:

    If you're trying to link a path to a drive, I think that subst might work or even psubst. I haven't used it in years.

    I know for a fact that I used mklink years ago when I set this up. Just apparently, I did something else also.



  • Already tried mklink /h?



  • @black3dynamite said in Windows 10 Junction on UNC path:

    Already tried mklink /h?

    That results in: Local NTFS volumes are required to complete the operation.

    Using UNC or mapped drive letter.

    Found an old post on here, and I used /D in that example.



  • When using /D, Windows works as expected, but Crashplan shows it as a 0 byte file.

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  • My hunch is that your symlinks are not fully enabled.

    Run this on the both sides (your computer running crashplan, and also the server you want your backups to reside on)

    fsutil behavior query SymlinkEvaluation
    

    You will likely find this:
    Local to local symbolic links are enabled.
    Local to remote symbolic links are enabled.
    Remote to local symbolic links are disabled.
    Remote to remote symbolic links are disabled.

    The "remote to" are your problem.

    Run this to enable them:

    fsutil behavior set SymlinkEvaluation R2R:1
    

    The quick way through is to just run this on both, but you may wish to run it on your workstation and try the backup, and then run it on your server is it still doesn't work.

    If this is a complete failure, I apologize 😉

    Edit: R2L at the other end....



  • @JasGot said in Windows 10 Junction on UNC path:

    My hunch is that your symlinks are not fully enabled.

    Run this on the both sides (your computer running crashplan, and also the server you want your backups to reside on)

    fsutil behavior query SymlinkEvaluation
    

    You will likely find this:
    Local to local symbolic links are enabled.
    Local to remote symbolic links are enabled.
    Remote to local symbolic links are disabled.
    Remote to remote symbolic links are disabled.

    The "remote to" are your problem.

    Run this to enable them:

    fsutil behavior set SymlinkEvaluation R2R:1
    

    The quick way through is to just run this on both, but you may wish to run it on your workstation and try the backup, and then run it on your server is it still doesn't work.

    If this is a complete failure, I apologize 😉

    Edit: R2L at the other end....

    Why isn't "Remote to" not enabled by default? Security?



  • @JasGot said in Windows 10 Junction on UNC path:

    My hunch is that your symlinks are not fully enabled.

    Run this on the both sides (your computer running crashplan, and also the server you want your backups to reside on)

    fsutil behavior query SymlinkEvaluation
    

    You will likely find this:
    Local to local symbolic links are enabled.
    Local to remote symbolic links are enabled.
    Remote to local symbolic links are disabled.
    Remote to remote symbolic links are disabled.

    The "remote to" are your problem.

    Run this to enable them:

    fsutil behavior set SymlinkEvaluation R2R:1
    

    The quick way through is to just run this on both, but you may wish to run it on your workstation and try the backup, and then run it on your server is it still doesn't work.

    If this is a complete failure, I apologize 😉

    Edit: R2L at the other end....

    No difference, but seriously good idea to check. Thanks.



  • Yes, I can copy the files to the local machine and let the backup take it from there. But I never had to previously. It, the script to copy the files, would just be one more point of failure.



  • @JaredBusch
    You can use BareMetal VHD loader to mount a vhd/vhdx on a network drive at startup, and Crashplan will see that as a local drive. link



  • Is Crashplan running as a particular user?

    If it's running as "System", it won't see the junction, will it?



  • Ok, so junction points don't support mapping to network path, symlinks do, and hardlinks can only be created for files, not folders. Try creating symlink and then create junction to the symlink and see if Crashplan can be fooled that way. So mklink /D C:\fake-Backup \\server01\Share\Subfolder and mklink /J c:\backup c:\fake-backup .