Hyper-V is Microsoft's new hypervisor-based virtualization product built into Windows Server® 2008. Virtualization is a powerful technology that enables consolidation of existing servers, business continuity through flexible data recovery capabilities, lower requirements for testing and development environments, and unique capabilities to make the management of branch offices easier than before.
Virtualization is a powerful option among the many different approaches to server consolidation. With Hyper-V, businesses can combine heterogeneous workloads while still maintaining isolation through the use of virtual machines. Not only does this approach increase the efficiency of existing hardware, it also reduces the total cost of ownership by reducing the overall cost of running a datacenter.
Leveraging virtualization for business continuity provides the capabilities of having a rapid backup-and-restore process, ideal for disaster recovery scenarios. With the virtualization stack in Windows Server® 2008, unique high-availability capabilities are available to businesses in the realms of both host clustering and guest clustering. These capabilities are important for addressing key recovery scenarios, from planned and unplanned downtime to failover load balancing.
Testing and Development
Testing and development traditionally have large hardware requirements, which can be minimized through the use of virtual machines. For testing and development, the use of virtual machines is ideal. They create distributed application environments and provide rapid-provisioning capabilities, and the disk-state features allow capturing point-in-time information.
Furthermore, due to the extensive Windows Management Instrumentation (WMI) interfaces that Hyper-V exposes, IT staff can enable automation and remote control of any virtual machines being used and drive them directly from their WMI-based testing suite or automated build tool.
Branch Office Management
Branch offices have multiple IT needs, often when there is little to no IT staff available. With Hyper-V, businesses can simplify branch office IT operations. Leveraging the benefits of virtualization, businesses can create a more agile infrastructure. New management capabilities allow IT staff to move virtual computers without affecting the users. Virtual computers are also able to automatically manage themselves.
Branch-office infrastructure can be consolidated in many ways by leveraging virtualization. Multiple virtual machines can be hosted on a single virtualization server, serving all branch office workloads. By doing so, branch offices can lessen their reliance on IT support. Another extension is the ability to ship out a "branch office in a box" containing a set of virtual hard disks to update the branch office rather than having to do physical upgrades directly on the machines themselves. Microsoft's virtualization offerings can also integrate into core IT services such as Active Directory and other Microsoft management technologies and tools.
Hyper-V is a role in Windows Server 2008 x64 editions and supports both 32-bit and 64-bit guests, while leveraging the new hardware-based virtualization technologies. It also provides the capability of supporting large memory (up to 64 GB per virtual machine), thus enabling the hosting of larger workloads in a virtual environment.
Also, to be able to scale better than previous Microsoft Virtualization offerings, Hyper-V provides symmetric multiprocessing capabilities for virtual machines (up to four-way per virtual machine). Pass-through disk access for virtual machines is also available in Hyper-V so that virtual machines can have access directly to a physical disk rather than being forced to use virtual hard disks.
Hyper-V also introduces a new architecture through the use of virtual service providers and clients. This new architecture provides a way for virtual machines to request access to shared hardware such as disk devices, networking devices, and so on, seeking the highest possible performance with lowest possible overhead.
As for the performance of the parent operating system itself, it is significant that Hyper-V can leverage the Windows Server 2008 Server Core minimal-install option. Server Core is a stripped-down version of Windows Server 2008 that provides a command-line interface (CLI) and only the most common server functions. This construction means that the parent operating system will have minimal consumption of resources as well as a small attack surface, making even more resources directly available to the virtual machines with less chance for the virtualization stack itself to be compromised.