According to this blog post it's possible and supported for you to move the INETPUB folder and its content from its default location on C: drive to a different volume:
However this is somewhat misleading as you can only copy INETPUB and not move it. As the fine print in red at the end of this blog post indicates, you must leave the original INETPUB folder structure in place afterwards because deleting it may break Windows servicing when software updates are applied to your IIS web server. So after patches are applied you may need to copy any updated files your original INETPUB folder structure to your mirror location on the other volume to ensure your web sites and web applications continue to function properly. But that means you're adding more administrative overhead, so a much better approach is to leave INETPUB where it is on C: drive and use virtual directories instead to relocate your web content to a different drive.
Mitch Tulloch is an eleven-time recipient of the Microsoft Most Valuable Professional (MVP) award and a widely recognized expert on Windows Server and cloud computing technologies. For more information see http://www.mtit.com.