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3 min read

Hyper-V in WS08 R2 Release Candidate: Bringing More to the Table


Here we are at the RC milestone of Windows Server 2008 R2, which usually indicates that we’ve hit the home stretch and we’re marching straight ahead to RTM. Generally that’s nothing new, but get set to smile, because this time we’re not just marching home, we’re adding new features, too!

So in addition to the cool features we’ve already announced for Hyper-V in Windows Server 2008 R2, including  live migration, clustered shared volumes, hot add/remove of storage and improved networking support, I’m hugely please to introduce 64 logical processor support and processor compatibility mode for live migration! These are hugely powerful features that add both scale and flexibility to future virtualization deployment efforts.

64LP Support

We have seen processors grow from 1, 2, 4, and now 6 cores on a single processor, soon to hit 8.  Within the Windows Server 2008 R2 lifecycle, 64 logical processor servers will become commonplace (8 processors x 8 cores).  Virtualization is the natural fit for these next-gen servers, allowing them to consolidate a greater number of virtual machines on a single host. Hyper-V is in line with these hardware trends all with an eye towards bringing you greater VM density. The dev team has done a fantastic job in building and testing a platform that can scale.

Let’s take a quick look at the history of logical processor support for Hyper-V:

  • Server 2008 Hyper-V                                         16 LP Support
  • Server 2008 Hyper-V +update (KB95670)      24 LP Support
  • Server 2008 R2 Hyper-V Original POR           32 LP Support
  • Server 2008 R2 Hyper-V RC/RTM                   64 LP Support!

That’s 4x the LP support from WS08 RTM! w00t!!


Processor Compatibility Mode for Live Migration 

Live Migration is the killer-feature in Windows Server 2008 R2!  Previous to the RC build of Windows Server 2008 R2, identical CPUs were needed across every node in the cluster in order to perform a live migration.  As we came closer to the RC milestone we got feedback from customers and partners asking, “What if I deploy additional nodes that contain newer processors with features not contained in the original nodes?”  Well, we’ve solved that problem due to tremendous effort by the Hyper-V development team.

Processor compatibility mode is very straightforward. It enables live migration across different CPU versions within the same processor family (i.e. Intel-to-Intel and AMD-to-AMD). However, it does NOT enable cross platform from Intel to AMD or vice versa. It works by abstracting the VM down to the lowest common denominator, in terms of instruction sets, which enables live migrations across a broader range of Hyper-V host hardware.

There are a few things to note: Processor compatibility mode is disabled by default but you can configure it on a per-VM basis. There are no specific hardware requirements other than the CPUs must support hardware assisted virtualization (i.e. Intel’s IVT and AMD’s AMD-V).

One Last Nod 

I also want to give a quick plug to a great friend and neighbor of Hyper-V, System Center Virtual Machine Manager 2008 R2. SCVMM R2 will also have a release candidate and is expected around 30 days after Windows Server 2008 R2’s RC. It has some great new capabilities like support for live migration, Clustered Shared Volumes (CSV), hot add/remove of storage and our network optimizations.

A couple of other  new and cool features coming in VMM 2008 R2, include new management functionality for storage migration (migrate storage of a running VM), SAN enhancements (iSCSI targets and SAN-based migration across clusters), rapid provisioning (template-based), maintenance mode (automate evacuation of VMs off of host machines), and host compatibility checks (live migration checks).

For more info check out SCVMM 2008 R2.

Many Links and Many Thanks 

For more info on these features check out the episode of Ask Ian embedded below , which features Jeff Woolsey; one of our masters of Hyper-V here at Microsoft.

Speaking of Hyper-V masters, I’d like to give a big shout out to Bryon Surace who gave me the skinny on all these new features!

One more tip of the hat to the folks at AMD for putting together the live migration video linked to earlier.

More info on Windows Server 2008 R2 Release Candidate can be found here. Also make sure to check out Microsoft’s Virtualization site for more information on Microsoft’s all-up virtualization solutions.
Ask Iain: Virtualization