One of the main benefits of virtual desktop infrastructure is the ability to run many virtual machines on a single host, making the most efficient possible use of the resources available. Although VDI administrators often focus on memory, CPU, and disk I/O consumption, it is also important to take measures to reduce your desktop operating system's footprint on the host server.
To the best of my knowledge, there is no such thing as an official Microsoft-approved method for minimizing Windows 8's footprint. Part of the reason for this is probably that every organization's needs are unique, and some organizations may require features that other organizations might disable to save space. As such, you should use the techniques that are the most appropriate for your organization.
One of the easiest ways to reduce Windows 8's footprint is to disable hibernation. That's because when Windows goes into hibernation, the operating system captures the state of your current session and writes it to a file called hiberfil.sys. This file is the same size as the system memory. For example, if a virtual machine were allocated 2 GB of RAM, then the hiberfile.sys file should also be 2 GB.
Every VDI environment is different, but there isn't typically a need to leave hibernation enabled. If you do decide to disable hibernation, you can do so by opening an elevated command prompt window and entering the following command:
Once you have disabled hibernation, you can delete the hiberfile.sys file from the root directory. If you try to remove this file without first running the command shown above, the hiberfile.sys file will reappear the first time that hibernation is used. If you are having difficulty running the command due to permissions problems, make sure that you are running the command from an elevated command prompt window.
Another way to reduce the Windows 8 footprint is by disabling virtual memory usage and then deleting the Pagefile.sys file. Although this technique does work, my advice is to use this only as a last resort.
The Pagefile.sys file exists to make up for shortages of physical memory. In a VDI environment, memory is often more of a limiting factor than disk capacity. As such, removing the Pagefile.sys file can be counterproductive.
If you do decide to remove the Pagefile, you can do so by right-clicking on the Start tile and then right-clicking on the System command found on the resulting menu. When the System dialogue box appears, click on Advanced System Settings. When you do, the System Properties sheet will appear. Click the Settings button found in the Performance section. When the Performance Options dialogue box appears, select the Advanced tab and then click the Change button.
Check the DriverStore
Another way you may be able to reduce the Windows 8 footprint is by getting rid of any unnecessary driver collections. Even a clean Windows 8 installation might have driver collections that are unnecessary. For example, Windows 8 includes its own printer drivers, yet many organizations prefer to use printer drivers that are supplied by the printer manufacturer. In those types of situations, you can delete the default printer driver collections.
There is a CodePlex tool called Driver Store Explorer that's helpful for identifying your drivers. The tool was developed for Windows 7, but it works fine with Windows 8 so long as you run it with administrative privileges.
Disable System Protection
Windows 8 includes a system protection feature that can be used to revert the system back to an earlier point in time. One of the best ways to reduce the operating system's footprint is to disable System Protection.
To do so, right-click on the Start tile, and then right-click on System. When the System dialogue box appears, click System Protection. You can use the resulting interface to disable System Protection.
As you can see, there are a number of things that you can do to reduce Windows 8's footprint. Although this article is by no means a comprehensive collection of footprint reducing techniques, they should go a long way toward helping you to reduce Windows 8's size. Some other steps that you might be able to use include verifying that the File History feature is turned off and decreasing the size of the browser cache.