Using PowerShell to take Virtual Server snapshots… (Part One)

As promised, I'm going to be dropping into a series of postings that are little more technical in nature. Considering that I've just come off of doing several PowerShell seminars. I thought it might be fitting to talk about a PowerShell topic. So... I decided to describe how PowerShell can be used to take snapshots of virtual machines that are running on a Virtual Server (VS). I warmly call this a poor man's VS backup solution. :>)

To complete this task, you will need to gather up the following:

1. Go grab some C# code that is on the "virtual_pc_guy" blog: Link

2. Compile this code in a dynamic link library (DLL), you will need this DLL to impersonate the COM security on the resulting VS object. The name that Ben uses for the DLL is "VSWrapperForPSH.dll".

3. Next, go grab the VSHADOW.EXE utility that comes with the VSS SDK: Link

4. Finally, go grab the latest version of robocopy.

Ok, so the first step to putting this script is to figure its logic, For example:

1. We need to take in parameters like the destination for the backup (I would also suggest an import file of servers).

2. Next, we need to load the VSWrapperForPSH.dll into the current PowerShell session.

3. Then, we need to create the Virtual Sever COM instance.

4. Next, we use the VSWrapperForPSH.dll to set the security on the VS object.

5. We need to then get a list of the VMs on the local VS server using the Net.WebClient class.

6. Finally we put in a whole bunch of logic to do the following for each VM:

a. Pause it

b. Take a snapshot (using vshadow.exe)

c. Un-pause it

d. Mount the snapshot

e. robocopy the snapshot to the desired location

f. Repeat

Ok, that's enough for tonight. In my next post, I will put together some of the code snippets.

• Microsoft