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Probably a fairly straight forward question, but;

At the moment I have 2 different shares on 2 different machines (one server 2008, the other W7) which are basically a "mirror" of each other that gets periodically synced.

What I would like to be able to do is merge the two contents of these folders so that they appear to be coming from the one location. Read-Write is important to an extent, though realistically it would probably only occur on one location.

Basically, I am looking to emulate unionfs in a Windows environment on my current network. Does anyone know of a solution or software that'll do this?


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There seems to be a project for this on google code: but it also doesn't offer a compiled binary download (not sure if it ever did) implying it is probably not production-quality. But if you're at home or something you could certainly give it a whirl

There is something like this for Windows 7 - depends on what client(s) are accessing said shares, but since you mention windows 7 in your post, this might apply:

Someone else points out that you can also use symbolic links to emulate this - e.g. if your shares are foo and bar, with directories A B C on foo an X Y Z on bar, symbolic link the x y z directories underneath foo (and the reverse on bar so people should see (in theory) all 6 directories underneath both shares.

Haven't tried any of these, though, just offering pointers.


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its called dfsr.

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You can use DSF to make a share folder that contains links to each of those two folders; but it can't create a single folder containing both sets of files. – Chris S Jul 1 '11 at 14:36
mis-read that one! dang can't even down vote myself on this one. – tony roth Jul 1 '11 at 14:52

There isn't a unionfs but you have an number of options:

  • Create a junction on diskA\folderB which maps to DiskB\FolderB
  • Mount DiskB into a mount point on DiskA (diskb needs to be a dynamic disk)
  • Use dfs and create a shares like

    • \\domain\share\folderA
    • \\domain\share\folderB
    • \\domain\share\folderC
    • \\domain\share\folderD
    • \\domain\share\folderE
    • \\domain\share\folderF

where you can locate folders a,b,c,d,e,f on whichever of the two disks you want, and even move them if a disk fills up.

None of these opciones makes complete use of both disks.

  • As a final option you can use windows to create a raid stripe set out of the two disks... it joins the two disks onto a single unit, but with a doubling of the risk of loosing data.


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