Opening a file's Shadow Copy if the current copy is in use

Malfist picture Malfist · Mar 18, 2009 · Viewed 7.5k times · Source

I'm trying to backup files on a server, but some of them are in use and cannot be opened. Instead, I'd like to open their shadow copy if the current copy is in use. How can I do this?

For reference, I'm using C# .net 3.5.

Answer

Tom picture Tom · Sep 7, 2010

This question is quite old already, so my answer might not be of much use to you, but SO being a Q&A site maybe it still helps someone else.

I can't / don't want to put down the entire implementation, but the procedure is goes something like this:

  1. You create a Volume Shadow Copy via the Volume Shadow Service Provider for the drive where your file to be read is located(this is well documented on MSDN, also there is a sample client that creates these shadow copies and will most likely be sufficient for you)

  2. Either make a persistent one, or use the "callback" mechanism (calls your app)

  3. Open the desired file via UNC paths and CreateFile (the UNC looks something like this: \\?\GlobalRoot\Devices\HarddiskVolumeShadowCopyXZY\yourpath\yourfile.yourextension)

  4. Do whatever you want with the file

  5. If you made a persistent VSC you should use the sample client to delete it after you're done

more info here: http://technet.microsoft.com/en-us/library/cc785914%28WS.10%29.aspx and here: http://msdn.microsoft.com/en-us/library/bb968832%28VS.85%29.aspx