Microsoft released significant details at WinHEC to hardware developers from all over the world about Microsoft's upcoming virtualization architecture. Microsoft's Windows Hypervisor will be a very significant entry in to the world of virtualization. Here are some of the key details
- Windows Hypervisor will be released 180 days after the release of Windows Longhorn Server
- New virtualization management platform
- Greater than 4 CPU and 4 GB RAM for virtual guests
- Hot plug virtual hardware architecture
- Full kernel and I/O optimization architecture for guest operating systems
With the new Windows Hypervisor architecture, Windows Longhorn Server operating systems will be released with kernel enlightenments* that optimize memory and CPU operations. In addition to these kernel enlightenments, I/O (Input/Output) operations for video, storage and networking will also be streamlined to minimize overhead on the virtual host. Older server operating systems like Windows 2000 and 2003 server will be retrofitted with just the I/O optimizations but not the full kernel modifications that optimize Memory and CPU operations. This means that Windows Server operating on top of Microsoft's upcoming Windows Hypervisor will have a distinct advantage over Windows Server running on top of other virtualization technologies that don't implement these optimizations in their Hypervisor.
While Microsoft will allow third parties to freely optimize their operating systems to run with these guest-side enlightenments on top of the Windows Hypervisor, other Hypervisors will not be able to implement host-side enlightenments without licensing. What this means is that if the Linux or BSD community wanted to modify the Linux or BSD kernel to make it work more efficiently on top of Windows Hypervisor, they could do that at no cost. But if someone like Xen Source or VMware wanted to make their Hypervisors support Windows Server guest-side enlightenments so that Windows guests will run faster, they will need to license that. When asked by a VMware engineer if Microsoft will support some future paravirtualization standard, the answer was not at this point. Without naming names, Microsoft indicated that certain commercial virtualization vendors have indicated an interest in licensing Microsoft's optimizations. Microsoft also indicated that they had not decided if they will assist in Linux Kernel modifications beyond providing the technical information to the Linux community.
* Microsoft's use of the word "enlightenment" is another name for paravirtualization which is a method for modifying an operating system's kernel to make it consume fewer resources in a virtual environment