Table of Contents - Published: January 2008

Introduction 4
Hyper-V Overview 4
Key Benefits 5
Reliability 5
Strong Isolation 5
Security 5
Performance 6
New Microkernelized Hypervisor Architecture 6
Leveraging Virtualization-Aware Hardware 8
Simplified Management with Familiar Tools 9
MMC Interface 9
Microsoft System Center 10
System Center Virtual Machine Manager 10
System Center Virtual Machine Manager Main Features 10
Microsoft System Center Operations Manager 11
Third party management solutions 11
Integrated Virtualization 11
System Requirements 13
Host Operating Systems 13
Guest Operating Systems 13
Processors 13
Shared Storage for Quick Migration 13
Usage Scenarios 14
Scenario: Consolidate Infrastructure, Application, and Remote Site Server Workloads 14
14
Key Consolidation Features 15
Scenario: Automate and Consolidate Software Test and Development Environments 17
18
Key Software Testing and Development Features 19
Scenario: Business Continuity and Disaster Recovery 19
Key Business Continuity and Disaster Recovery Features 19
Scenario: Enabling the Dynamic Data Center 21
Microsoft System Center Integration and the Dynamic Systems Initiative 21
Key Dynamic Data Center Features 22
Conclusion 23
Introduction
Today’s data center is a complex ecosystem where different kinds of servers, operating systems, and applications interact with a wide variety of desktop computers and mobile client computers. IT departments are under increasing pressure to manage and support this assortment of mission-critical technologies, while controlling costs and maintaining reliability and security. Deploying server virtualization technology—moving disparate servers to virtual machines (VMs) in a centrally managed environment—is an increasingly popular option for facing these challenges.
With its built-in server and presentation virtualization technologies, Microsoft® Windows Server® 2008 enables you to reduce costs and increase hardware utilization, as well as accelerate and extend application deployment and access, while improving server and application availability.
Windows Server 2008 includes Hyper-V ™, a powerful virtualization technology that enables businesses to take advantage of virtualization’s benefits Hyper-V reduces costs, increases hardware utilization, optimizes business infrastructure, and improves server availability. Microsoft Hyper-V™ Server offers Hyper-V functionality in a standalone package for dedicated virtualization hosts.
This white paper introduces Hyper-V as an important component of the Microsoft desktop-to-data-center virtualization strategy and the Dynamic Systems Initiative (DSI), moving network and service management toward self-managing, self-healing systems. New and enhanced features in Hyper-V help relieve enterprise customer pain points in common scenarios: server consolidation, business continuity/disaster recovery management, testing and development, and the dynamic data center.
Hyper-V Overview
Virtualization is a widely adopted solution. Around 75 percent of organizations are using or evaluating virtualization and seeing its advantages for server consolidation, centralized management, and cost-reduction due to reduced hardware, power and cooling requirements. . As these benefits drive profit, companies want to virtualize more demanding workloads. They want more powerful and flexible virtualization solutions that are better integrated with their management tools. Wide adoption of 64-bit, multi-processor, multi-core servers spurs demand for virtual machines that are better able to take advantage of more scalable server hardware.
In light of these developments, Microsoft created Hyper-V, a next-generation, hypervisor-based virtualization technology that provides a reliable virtualization platform and and integrated management that enable customers to virtualize their infrastructure and reduce costs.
Key Benefits
Windows Server 2008 Hyper-V technology simplifies the interaction between hardware, operating systems, and virtual machines, while simultaneously strengthening the core virtualization components.
Reliability
Hyper-V provides better reliability and greater scalability that allows you to virtualize your infrastructure. It has a thin micro-kernelized hypervisor architecture with minimal attack surface. This hypervisor does not include any third party device drivers. It leverages the vast majority of device drivers that have already been built for Windows. Hyper-V is also available as a Server Core role.
Strong Isolation
Server virtualization enables potentially resource- and control-intensive applications to coexist on the same server. Virtual servers must be able to do their work with as much flexibility as possible, leveraging as much hardware capacity as they need, without conflicting with other virtual servers.
Hyper-V works with virtualization-aware hardware to tightly control the resources available to each virtual machine. For example, virtual machines are isolated in a way that gives them very limited exposure to other VMs on the network or on the same computer.
Security
Security is a central challenge in every server solution. Virtual servers are at least as exposed as their stand-alone counterparts and, in many ways, more exposed. For example, multiple server functions on one computer can mean more administrators have access to that computer. Third-party software and drivers can present security risks as well, so it’s important to make sure that, if a virtual machine is compromised, it has limited exposure to other virtual machines on the same physical server.
Virtualization provides an opportunity to increase security for all server platforms. Features that
Hyper-V uses to enhance security include:
Enabling VMs to take advantage of hardware-level security features, such as execute disable bit (preventing execution of the most prevalent viruses and worms), available in newer server hardware.
Providing strong role-based security to prevent exposure of secure VMs through shared servers.
Integrating network security features that enable automatic Network Address Translation (NAT), firewall, and Network Access Policy protection (quarantine).
Reducing the attack surface through a streamlined, lightweight architecture.
Performance
Performance advances and integration with virtualization-aware hardware enable Hyper-V to virtualize much more demanding workloads than previous virtualization solutions and to give them more resources for greater scalability.
Performance advancements include:
Speed enhancements through lightweight, low-overhead virtualization hypervisor architecture.
Multi-core support, giving each VM access to as many as four logical processors.
Enhanced 64-bit support, enabling VMs to run 64-bit operating systems and to access very large amounts of memory (up to 64 GB per VM), enabling more resource-intensive workloads and helping avoid slowdowns due to paging.
Microkernelized hypervisor architecture, enabling VMs to cut out layers of emulation and drivers, working more closely with virtualization-aware hardware.
A high-performance, hardware-sharing architecture that optimizes data transfer between physical hardware and virtual machines.
New Microkernelized Hypervisor Architecture
Hyper-V uses 64-bit hypervisor-based technology to give VMs running Windows Server 2008, Windows Server 2003, specific Linux distributions, or Xen-enabled Linux the ability to work as closely with CPUs and memory as possible in a shared environment, vastly increasing performance.
Hypervisor-based virtualization is the latest stage in virtualization technology’s evolution, from emulated environments, which began more than 30 years ago, to today’s hardware-enhanced, close-to-bare-metal virtualization.
Basic virtualization (Type 2 virtual machine) places a thick, relatively slow layer of abstraction between hardware and guest operating systems. This approach is called hosted virtualization. The virtual machine monitor (VMM) runs as an application on an operating system, and each VM runs on top of the VMM. As a simplified example of the overhead involved in this type of virtualization, a hardware call from a guest operating system’s device drivers:
Goes first to emulated virtual hardware managed by the VMM.
The VMM routes it to the operating system.
The operating system routes it to the hardware’s device driver.
The hardware’s device driver routes it to the hardware.
The process happens in reverse for any responses from the hardware.
Newer, Hybrid virtualization architectures, including that used in Virtual Server, run side by side with server operating systems.
In Type 1 virtual machine monitors, the hypervisor sits at the level closest to the hardware, sometimes called the
bare-metal level.
There are two kinds of hypervisor architectures – monolithic hypervisors and micro-kernelized hypervisors (see graphic below). The monolithic hypervisor model still places large amounts of code between hardware resources and virtual machines, because the virtual machine monitor emulates hardware for its VMs. When a guest operating system makes a hardware call through its device drivers:
The VMM’s emulated hardware intercepts the call.
The VMM routes it to the device drivers, necessitating numerous expensive context switches.
The device drivers route it to the physical hardware.
This approach, called a
monolithic hypervisor, includes hardware drivers in the hypervisor. Examples of monolithic hypervisors include VMware’s ESX Server.
Windows Server 2008 Hyper-V uses a micro-kernelized hypervisor model. In a micro-kernelized hypervisor, the only layer between a guest operating system and the hardware is a streamlined hypervisor with simple partitioning functionality. The hypervisor has no third-party device drivers. In addition to improved performance, it has an inherently more secure architecture with a minimal attack surface. The drivers required for hardware sharing reside in the host operating system, which provides access to the rich set of drivers already built for Windows.
Figure 1. Approaches to Hypervisors: Monolithic Hypervisor’s contain its’ own driver stack as a part of the hypervisor; Microkernelized Hypervisor’s has a minimal hypervisor layer and leverages the parent partition and provides an inherently more secure architecture with minimal attack surface
Leveraging Virtualization-Aware Hardware
The new generation of 64-bit server hardware includes virtualization-aware processors.
Intel® Virtualization Technology and AMD Virtualization (AMD-V) are able to manage some memory- and hardware-sharing functions that would otherwise be left to the server’s virtualization management software.
Hyper-V requires a processor with hardware-assisted virtualization functionality, enabling a much more compact virtualization codebase and associated performance improvements.
With the availability of these new processors and a new, hypervisor-based virtualization architecture, Hyper-V is able to put virtualized applications as close to bare metal as possible. This enables virtualized applications to take advantage of features like multi-core processing that would be available on a standalone, physical server but haven’t up to this point been available inside a virtual machine.
Benefits of the new approach include previous solutions’ single-processor/single-core VM being supplanted by support of up to four cores per VM with Hyper-V.
Table 1
Virtual Server
|
Hyper-V
|
Processor Support
1 processor/core per VM
|
Processor Support
Up to 4 logical processors per VM
Up to 16 processing cores in the physical machine.
|
Type of Virtual Machines Supported
32-bit VMs
|
Types of Virtual Machines Supported
32-bit VMs
64-bit VMs
32-bit and 64-bit VMs running simultaneously
|
Maximum Memory per Virtual Machine
3.6 GB
|
Maximum Memory per Virtual Machine
Up to 64 GB
|