Review: Microsoft Hyper-V 2012 narrows the gap
Windows Server 2012 Hyper-V combines easy setup and management with new features that lower the entry barrier to highly available virtualization clusters
Installation and configuration
Hyper-V 2012 couldn't be any easier to install in Windows Server 2012. Simply choose the Hyper-V role from the Server Manager application, click through a few screens, and you're done. Be aware that the install will require a reboot of your server. You'll need to go through a few basic configuration steps before you can actually deploy VMs on your new Hyper-V installation. All Hyper-V 2012 VMs require a virtual switch connection in order to communicate over the network. Because a virtual switch must be connected to an underlying network interface for a physical connection, you must configure this connection after Hyper-V is installed.
While included in Windows Server 2012, Hyper-V 2012 is also available in a free stand-alone version. This product essentially installs a server-core version of Windows Server 2012 with a minimal user interface. It's intended to be managed remotely, with just a few options and controls available from the console. These include details such as changing the computer name, networking configuration, enabling remote desktop, and powering down the system. Adding a Hyper-V Server 2012 host to the management console on another Windows Server 2012 machine requires merely a right-click and the entry of the Hyper-V server's IP address.
New and improved
A number of new capabilities introduced in Hyper-V 2012 extend existing features. For example, live migration of running VMs, which previously required shared storage, can now be done in a nonclustered environment. This feature is called "shared nothing migration" in some circles. Live storage migration -- a new feature that aims at parity with VMware -- makes it possible to move the virtual hard disks in use by a running VM to a different storage device. These two features combined make it possible to move running VMs between any connected machines on a domain.
Hyper-V Replica, which provides unlimited, host-to-host replication of virtual machines without shared storage, brings Microsoft up to par with other virtualization vendors in the area of redundancy. The ability to store Hyper-V disks on SMB shares is yet another feature that delivers a new level of resiliency in the form of Cluster Shared Volumes for SMB file stores. Cluster Shared Volumes essentially eliminates the need for high-cost storage to deploy an HA virtualization solution. The new Hyper-V Extensible Switch provides a platform upon which networking vendors can build new functionality. Hyper-V switch extensions might include network-based virus protection or intrusion detection solutions, for example.
On the numbers front, there are gains in the amount of memory an individual guest can support (1TB vs. 64GB in Windows Server 2008 R2), logical processors per host (320 vs. 64), and nodes per cluster (64 vs. 16). The total number of virtual processors per host is now 2,048, up from 512 in Windows Server 2008 R2. A single host can now support up to 1,024 active VMs as opposed to 384 in the previous release. Support for Non-Uniform Memory Access (NUMA) inside virtual machines is new to Hyper-V 2012 as well.
Managing Hyper-V 2012
Microsoft has two basic paths for managing Hyper-V 2012 out of the box, using either the graphical user interface Hyper-V Manager or PowerShell. Either way, the work gets done with PowerShell commands and scripts behind the scenes. The real power behind both management paths is the ability to manage multiple machines from a single console. Hyper-V Manager can manage any number of different Hyper-V hosts, all from within the same console. Even for small deployments, managing Hyper-V through Hyper-V Manager is much more efficient than remotely logging into each machine. The wizard-based approach to guiding you through most of the management tasks helps fledgling Hyper-V administrators get the job done.