Integration of Hypervisor Technology in Windows Server 2008

To leap beyond its competition in the area of server virtualization, Microsoft had to make some significant changes to the operating system that hosted its next-generation virtual server technology. With the original Windows 2008 in development, Microsoft took the opportunity to add in a core technology to Windows 2008 (and extended it in Windows 2008 R2) that provided the basis of Microsoft’s future dominance in server virtualization. The core technology is called hypervisor, which effectively is a layer within the host operating system that provides better support for guest operating systems. Microsoft calls their hypervisor-based technology Hyper-V.

Prior to the inclusion of Hyper-V in Windows 2008 and Windows 2008 R2, the Virtual Server application sat on top of the host operating system and effectively required all guest operating systems to share system resources, such as network communications, video-processing capabilities, memory allocation, and system resources. In the event that the host operating system has a system failure of something like the host network adapter driver, all guest sessions fail to communicate on the network. This monolithic approach is similar to how most server virtualization technologies operate.

Technologies like VMware ESX as well as Hyper-V leverage a hypervisor-based technology that allows the guest operating systems to effectively bypass the host operating system and communicate directly with system resources. In some instances, the hypervisor will manage shared guest session resources, and in other cases will pass guest session requests directly to the hardware layer of the system. By providing better independence of systems communications, the hypervisor-supported environment provides organizations better scalability, better performance, and, ultimately, better reliability of the core virtual host environment.

Hyper-V is available in Windows Server 2008 R2 Standard, Enterprise, and Datacenter Editions. Each of these SKUs are available with and without Hyper-V.

Hyper-V in Windows Server 2008 R2 is only supported on x64-bit systems that have hardware-assisted virtualization support. CPUs must support Intel VT or AMD-V option and Data Execution Protection (DEP). Also, these features must be enabled in the computer BIOS. Fortunately, almost all new servers purchased since late 2006 include these capabilities.

Source of Information : Sams - Windows Server 2008 R2 Unleashed