Ideas on how to save space with Windows 2008 R2 server on Hyper-V?

Question

I've got this question awhile ago, but it still bothers me.

I work with a few virtual machines running Windows 2008 server, mostly demo VMs and test machines. Since most devs use them, I prefer to not have individual setups here and there and maintain a catalog of exported VMs and hard drive images instead.

Thanks to side-by-side assemblies and windows updates each server carries an overhead of about 6 - 12 Gigs in side-by-side folder (winsxs) and windows update.

Suppose I have 50 exported VMs (with their images), each has about 3 Gigs of payload data (OS, programs, data) and about 12 Gigs of shared overhead, which is mostly the same for all these VMs. Then I waste 2/3 of my storage space (about 600 Gigs total), not to mention network overhead of pushing this redundant data around the network when a dev wants to download a new VM snapshot.

So I am thinking of a way of consolidating the winsxs folder accross multiple VMS. Ideally, I'd like to come up with some shared drive or something. I am even willing to designate a physical device for this.

I realize that Windows server has minimum requirements and these files cannot be deleted (http://social.technet.microsoft.com/Forums/en-US/itprovistasetup/thread/9411dbaa-69ac-43a1-8915-749670cec8c3).

I also found a post on moving winsxs folder, but it does not appear as a reliable solution.

Does this sound even remotely feasible? What are the best practices for consolidating resources across VMs?

Thank you almighty stackoverflow gurus for your prompt attention ;-)

Answer 1

Don't touch the WinSXS folder.

It's not as big as it looks (alot of it is hard links to duplicate files)

If you wanted to have consolidated space, use differencing disks--create one VM with Windows on it, and then use that disk as the basis for the rest. Each disk will only store the delta between the original and where that VM goes after that.

It is not possible to share WinSxS folders across installations.

If you want to know more about how WinSxS works, check out my blog post: http://fearthecowboy.com/post/CoApp-FAQ-Can-you-explain-how-Side-by-side-%28WinSxS%29-works.aspx