Review: Microsoft Hyper-V Server 2008 R2

The first implementation of Microsoft's free standalone hypervisor, Hyper-V Server 2008, was, let's face it, a little disappointing, with limited scalability and no Quick Migration support like that in the full implementation. The R2 release, however, has a lot more going for it, including Live as well as Quick migration options. But it's not all good news, especially if you're looking for a complete virtualisation solution, which Hyper-V Server 2008 R2 is not.

What you get with the R2 release is more or less the same, now very scalable, hypervisor as in the full Windows Server 2008 R2 product. That means the ability to run on hosts with up to eight processors and 1TB of RAM, as well as live migration of virtual machines and support for the Windows failover clustering which is needed to enable it.

You don't get the Windows guest licences included in the full Server package, but it is free, requires far less server resources and is very easy to deploy.

We simply downloaded the ISO image from the Microsoft web site, burned it to DVD, and then used that disk to boot our test server. There was no need for a host operating system and the setup process was much like installing an ordinary Windows server, only much quicker and with far fewer questions to answer.

In all it took us around 20 minutes, after which our server rebooted and the hypervisor was up and running. At which point, unfortunately, we came face to face with one of the biggest drawbacks: the lack of any bundled management tools.

Unlike the free ESXi hypervisor from VMware or XenServer from Citrix, all you get from Microsoft is the hypervisor together with an implementation of Windows Server Core. There's no GUI or management tools of any description, just a simple text-based configuration utility to give the server a name, join it to a workgroup or domain, change the network settings and so on.

Fortunately, if you're an enterprise customer deploying Hyper-V Server alongside servers running the full Windows Server 2008 product, that's not a problem. You can use your existing Hyper-V and Failover Cluster manager tools to handle standalone hypervisors. Likewise, if you're using System Center Virtual Machine Manager 2008, that too can be used with Hyper-V Server. However, the R2 implementations of both are needed for the R2 hypervisor and, if you're a small business looking to deploy just one or two hosts, the extra cost involved can be significant.

Another solution is to download the so-called Remote Server Administration Tools (RSAT), a collection of remote server management utilities available for free download.

However, that's not quite as simple as it sounds as you can't use the current Vista version to manage the R2 release. Instead we had to download a newer implementation of RSAT, only available for Windows 7. And that meant sourcing a Windows 7 PC and locating the download which, when we looked, wasn't signposted from the Hyper-V Server page. We eventually found it here. Added to which we encountered a number of issues getting the new RSAT implementation to work.

The problem here was that we only had one host server and a Windows 7 workstation on our test network, so we opted for a simple workgroup rather than an Active Directory domain setup. Unfortunately, that led to all sorts of hiccups when we tried to connect the Hyper-V Manager on our Windows 7 PC to the hypervisor.

Initially we didn't have sufficient rights, which wasn't hard to fix, but then we started to get messages telling us that the RPC service on the server wasn't running, even though it was. A bit of searching revealed that other testers had encountered similar problems, but despite trying all of the suggested workarounds we couldn't get it to work.

In the end we simply had to admit defeat, plug a Windows domain controller into our LAN and add both the server and Windows 7 PC to an Active Directory domain. After that it all worked fine and we were able to use the Hyper-V Manager in RSAT to remotely create, run and manage virtual machines on our standalone hypervisor.

We wasted several hours getting to this stage, but once it was working we found the setup easy to manage and were impressed by what the new Hyper-V Server has to offer.

As already mentioned, the updated hypervisor is a lot more scalable with support for four times the number of host processor cores (up from 16 to 64). With the right hardware that means a lot more virtual machines, with the R2 hypervisor able to handle up to 384 virtual machines (VMs) per server, double the previous limit, with a total of 512 virtual processors shared between them.

On the downside the number of NICs required would make coming anywhere close to these limits unlikely, but each VM can have up to 64GB of memory and 2040GB of disk space, which is a pretty weighty spec. Moreover, you get the same quick/live migration support as on the full server implementation with no significant differences that we could find in terms of either performance or how the different hypervisor implementations are managed.

That said, the problems we encountered getting to grips with the standalone Hyper-V hypervisor, the sparse documentation that accompanies it and the lack of bundled management tools made it clear that it can’t be viewed as a complete standalone solution.

If you’re determined you can always add the free tools yourself to build a self-contained platform. But Microsoft doesn’t make it easy and, it seems, would much rather Hyper-V Server be used as a low-cost way of adding additional hypervisors to an existing Windows Server 2008 installation.

You can also read our full Windows Server 2008 R2 review, where there's more on the Microsoft hypervisor changes.

X64 compatible processor with Intel VT or AMD-V technology enabled. 2GHz or faster processor recommended. Minimum 1GB RAM - 2GB or greater recommended (additional RAM is required for each guest operating system); maximum 1TB. Minimum 8GB disk space - 20GB or more recommended (additional disk space needed for each guest operating system). Remote management tools required, available separately.