SearchSystemsChannel.com's Pat Ouellette: What are the key new Hyper-V R2 features that solutions providers should be aware of?
Greg Shields: In Hyper-V R2, the first feature solutions providers need to be aware of is true Live Migration [as opposed to quick migration in R1]. So, with the RTM version of 2008, when a migration occurred, there would be a very short period of downtime. Migrating virtual machines for planned outages would require some number of seconds of outage for those machines to migrate.
The new Hyper-V R2 features now have true Live Migration, which means that the VMs are going to migrate and have essentially an imperceptible amount of downtime to go from one host to the other. That's very important.
Cluster Shared Volumes are [another] key Hyper-V R2 features. With the original RTM version of Windows Server 2008, the unit of migration for the cluster was the individual disk. So if you wanted to migrate an element in that cluster, you would have to migrate the entire disk resource from node to node. Unfortunately, that meant that if you had multiple VMs on the same disk resource, then all of those VMs would have to migrate at the same time. That's a big lump of computers that need to migrate at the same time, and that really made it very difficult for solutions providers to manage.
CSVs actually allow the cluster to see the individual VM disks that are on that connected lens. So the unit of migration is no longer the disk, but the actual individual VM files that are on that disk. This means you can migrate one VM at a time, as opposed to the entire disk resource, and you don't have to manage lots and lots of VMs at the same time. CSVs really improve the management of those VMs.
A third key Hyper-V R2 feature has as much to do with Windows Server as it does with Hyper-V. Hyper-V R2 now supports "second-generation processor instruction sets." Microsoft refers to these as the Second Level Address Translations (SLATs). These are like the Intel-EPT and the AMD-RVI instruction sets. The new instruction sets make certain kinds of workloads perform much, much faster and allow you to virtualize more of your customer's environment than you might not have been able to before.
About the expert
Greg Shields is an independent author, instructor, Microsoft MVP and IT consultant based in Denver. He is a co-founder of Concentrated Technology and has nearly 15 years of experience in IT architecture and enterprise administration. Shields specializes in Microsoft administration, systems management and monitoring, and virtualization. He is the author of several books, including Windows Server 2008: What's New/What's Changed, available from Sapien Press.
This was first published in April 2010