I have been doing some application testing using Hyper-V 6.1 virtual machines.  I have Hyper-V installed on a Win 2008R2 server. I have three VMs configured and running with snapshots.  Once I install the application and then revert back to a snapshot prior to the application install, one of my VMs works as advertised and does not have the application installed which is what I would expect and what I found in my original testing of the snapshot / revert functionality.  The other two have all the changes I have made to the VMs back through all the snapshots all the way back to the original VHD file, which never had the application installed.  

I would try to delete the snapshots trying to get back to an instance of the VM that did not have the application installed on it but I could not on two of my VMs.  I eventually deleted all the snapshots so I was back to using the original VHD file (no avhd files left in the Virtual Hard Disks folder).  Now the original VHD file had all the updates and changes that all the snapshots (avhd files) had.  I know there is a way to purposely make the changes fold back into the original vhd file from the avhd files but I certainly did not attempt it.

How does this happen and how can I stop it?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

very strange, there must be something that was not done right,
repeat your tests, deleting a snapshot will not take you back to the previous state, you need to choose (apply ) when you select a snapshot to do an actual revert to previous state.
also keep in mind when you delete a snapshot , you need to shutdown the vm to allow the avhd file to be merged to the original vhd file. you will see the status on Hyper-V manager.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
BrianSDGAuthor Commented:
Sorry for the delay.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.