Clearly an administrator needs a software package capable of managing a sprawling environment full of virtual machines; Microsoft's System Center Virtual Machine Manager (SCVMM) 2008 R2, delivered in August 2009, is the software giant's latest response.

SCVMM is specially designed to work with Hyper-V, Microsoft's flagship hypervisor, which was newly updated for the fresh Windows Server 2008 R2 operating system release. But it also boasts the ability to manage both VMware and Hyper-V environments, a feature not found in VMware's management tools. Contrary to some printed reports, SCVMM does not support Xen.

Let's take a look at what SCVMM 2008 R2 can do.

Live migration and other 'hot' features

One of the biggest improvements in Hyper-V 2.0 is the ability to move virtual machines from one physical machine to another, while the VMs are running, with no loss of service. VMware's tools and products have had this ability, called VMotion, for some time, but live migration is new to the Hyper-V platform.

The biggest feature of SCVMM 2008 R2 continues to be its ability to assist with these live migrations, with essentially one- or two-click access to move a virtual machine from one host to another with no perceptible loss of connectivity, performance or other interruption. Although live migration works with bare Hyper-V using the free tool, SCVMM makes it easier, with better intelligence about the target virtual host to which you're migrating, available resources and other information.

SCVMM also interfaces with the failover clustering features of Windows Server 2008 R2 to make clustered virtual machines fault-tolerant, even across data centres and different geographic locations (bandwidth obviously being a potential limitation).

Further, SCVMM 2008 R2 also now allows the addition and removal of storage to virtual machines without interruption. This is useful when scaling capacity for certain disk intensive workloads, and SCVMM makes it a relatively simple task to manage virtual hard disks and iSCSI passthrough disks on a "hot" basis without requiring reboots or other service interruptions.

Storage management has long been a frustration in Windowsland, and it's still not the easiest thing in the world, but SCVMM improves upon the process somewhat in this release.