With the release of Windows Server 2008 R2 this fall, Microsoft is ushering in a surprisingly comprehensive update to its core Windows Server product. But no Windows Server technology is arguably as central to the software giant's strategy as the Hyper-V hypervisor-based virtualization platform, and Hyper-V has gotten a major makeover in its 2.0 release.

Available both as part of the wider Windows Server 2008 R2 release (as Windows Server 2008 R2 Hyper-V 2.0 ) and separately as a standalone bare metal server (as Microsoft Hyper-V Server 2008 R2), Hyper-V 2.0 is a solid foundation for virtualized environments of all kinds. Here's what you need to know about Hyper-V 2.0.

How to Acquire Hyper-V 2.0
Hyper-V 2.0 is available as an installable role in Server 2008 R2 Standard, Enterprise, and Datacenter Editions. It is also available as part of the midmarket-oriented Server 2008 R2 Foundation Edition, and as a free, bare-metal standalone server called Microsoft Hyper-V Server 2008 R2. Note that all of these products are available only in 64-bit versions.

Hyper-V 2.0 High-Level View
As with the original Hyper-V release, which shipped as part of Server 2008, Hyper-V is a hypervisor-based server virtualization platform.

It provides the ability to run virtualized client and server guest OSs under the host Server 2008 R2 OS (or, in the case of Microsoft Hyper-V Server 2008 R2, under that basic host OS), and can form the basis of a virtualized infrastructure in which you can consolidate older servers, deploy and manage new server installations, and perform other tasks traditionally associated with physical machines.

Hyper-V 2.0 has been streamlined across the board to run effectively in a variety of environment types, from small-to-midsized businesses (SMBs) to the largest data centers.

What's New in Hyper-V 2.0
Live Migration is arguably the signature new feature in Hyper-V, and it significantly closes the gap between this solution and VMware’s more mature virtualization products.

Live Migration provides a way to move a running virtual machine (VM) from one physical host server to another in near real-time, with no service interruption to connected clients. (Previously, in Hyper-V1.0, Microsoft provided a less capable but related feature called Quick Migration.)

Hyper-V 2.0's Live Migration functionality works with another new feature of the underlying Server 2008 R2 platform, Cluster Shared Volumes, to provide failover capabilities as well. However, each server must exist within the same failover cluster and access the same shared storage.

From a scalability perspective, Hyper-V supports heady resource allotments, and with this release, the bare-metal Microsoft Hyper-V Server 2008 R2 product corresponds to the specifications of the broader Server 2008 R2 platform (whereas the first version was far more constrained). It supports up to eight physical processor sockets (64 for Datacenter Edition), up from four. Processor core support is also up dramatically, to 64.

The original shipping version of Hyper-V 1.0 supported 16 processor cores, though that was later increased to 24 via a software update. The maximum number of virtual processors is eight times the number of logical processors (essentially equivalent to the number of physical processor cores).

Additionally, Hyper-V 2.0 supports up to 1TB of RAM, and up to 16 cluster nodes. (Note that cluster nodes aren’t supported in Microsoft Hyper-V Server 2008 R2.) The maximum number of running VM guests is 384, up from 192 in Hyper-V 1.0.

Hyper-V 2.0 also improves virtual networking performance via several new networking advances, including VM Chimney, which provides TCP offloading functionality that maps virtual network traffic to a specific physical NIC.

And in Hyper-V 2.0, the Jumbo Frames feature that was introduced in Server 2008 is available to VMs as well, improving network throughput and reducing CPU utilization.

Microsoft Hyper-V Server 2008 R2 VS. Hyper-V 2.0 in Windows Server 2008 R2
Although Hyper-V 2.0 in Microsoft Hyper-V Server 2008 R2 is largely identical to that in the mainstream Server 2008 R2 editions, it is also different.

Microsoft Hyper-V Server 2008 R2  supports clustering, for example, but doesn’t include any virtualization rights for guest VMs. (Server 2008 R2 Enterprise Edition comes with four VM licenses, while Datacenter Edition ncludes unlimited VM licenses.)

For admins, the biggest difference is that Microsoft Hyper-V Server 2008 doesn’t include a local administration console. Instead, this free server provides a simple command-line–based tool for making simple configuration changes only (i.e., setting the machine name and joining a domain).

To manage Microsoft Hyper-V Server 2008 R2, you need to do so remotely using Microsoft Remote Server Administration Tools (RSAT) in Server 2008, Server 2008 R2, or Windows 7. (For the latter, a separate download is required.)

Recommendations
Hyper-V 2.0 is a major improvement over its predecessor and a credible challenger to the entrenched VMware solutions with which it competes. From a performance and scalability perspective, Hyper-V 2.0 makes upgrading a no-brainer for existing customers.

But the product is particularly compelling for new customers as well: The free, standalone Microsoft Hyper-V Server 2008 R2 is now largely equal to the functional capabilities of its more expensive siblings, though of course you'll need another server, or RSAT, to administer the server. Either way, it's the perfect way to get your feet wet with Microsoft's virtualization platform.

What you'll discover is an environment that’s nearly as mature and full-featured as anything offered by VMware (assuming your business is a Microsoft shop and not as concerned about cross-platform capabilities). With Hyper-V 2.0, Microsoft finally has a credible alternative to the virtualization market leader, and it’s built on top of the Windows Server platform you already know and trust.