Viridian Is Huge Draw for Windows Server 2008

Review: While the CTP release of Microsoft's new hypervisor is not without wrinkles, the new feature promises to expand the reach of enterprise server virtualization options.

Microsofts Windows Server 2008 RC0 hit the Web earlier this week on the road to its scheduled February 2008 release, toting a new Internet Information Services role for the products lean and mean Server Core incarnation and a laundry list of small fit-and-finish tweaks.

However, the most significant component of the RC0 code drop is one that wont go gold until three or so months after Server 2008 hits general availability: Microsofts brand-new virtualization services feature, also known as "Viridian."

Based on my first few days of Viridian testing, I can report that Microsofts new hypervisor technology is off to a solid start—the code is certainly much more polished than, for example, the first few iterations of the open-source Xen hypervisor project.

Microsoft has done a good job of integrating its virtualization services into the same framework of easy-to-manage server roles that govern Windows Servers other key functions, and I found that Viridians facilities for creating and monitoring virtual instances compared well to rival products from VMware and XenSource.

Of course, my early tests of Microsofts new virtualization feature have not been wrinkle free—the firm has labeled this initial public release of Viridian as a Community Technology Preview, and the CTP moniker is a fitting one. For instance, Viridian cannot yet import pre-existing virtual instances stored in Microsofts Virtual Hard Drive format, and I experienced some issues enabling networking support for the Windows and Linux guests with which I tested.


With that said, I expect Microsofts new virtualization bits, which will eventually ship with every copy of Windows Server, to expand significantly the reach of server virtualization and to give enterprises a viable third option to the VMware and Xen-based hypervisor options that are currently available.

Welcome to the (Virtual) Machine

I managed to install Windows Server 2008 RC0 on a dual-core x64 processor-powered machine with hardware virtualization extensions—Windows virtualization is 64-bit only, and, unlike VMwares ESX Server, Viridian will not function on older machines that lack these extensions.

While the so-called community technology preview version of Microsofts new hypervisor rides with Windows Server 2008 RC0, the new Microsoft virtualization bits arent, strictly speaking, part of RC0. The upshot of this is that I had to install a couple of update packages before installing Windows new virtualization role through the systems Server Manager.

The release notes for RC0 counseled me to update my system BIOS before firing up the hypervisor, but since Id managed successfully to test a version of XenSources XenEnterprise product on the machine Id set aside for Server 2008, Id tried skipping this step.


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However, just before I launched my first virtual instance, Windows warned me that its hypervisor was not running. The prescribed BIOS upgrade got me up and running, but I would have liked to have seen Windows Server Manager prompt me earlier that my hardware configuration was amiss.

I installed guest instances of Windows Server 2008 RC0, of Windows Server 2003 and of an rPath Linux-based Mediawiki appliance on my Windows virtualization host.

The rPath installers Linux kernel panicked shortly after boot, but I took the advice of the kernels error message and rebooted my instance with the kernel flag "noapic." My installation then proceeded normally. However, once I had the Linux instance up and running, I noted that my guest failed to recognize the virtual network adapter Id assigned to it with Windows Server 2008s well-appointed instance configuration tools.

Similarly, the Windows guests Id installed did not immediately recognize their virtual network interfaces. However, Windows Server 2008 gave me the option of connecting a virtual Integration Services Setup Disk that contained virtualization-savvy drivers to my guest instances.

Id installed my Server 2008 guest instance in its stripped-down Server Core configuration, so I could not navigate graphically to the virtual disk Id connected. I was, however, able to navigating over to the "D:" drive from the Windows command line, and down into the virtual disk to locate and run the appropriate setup file for installing the drivers I needed.

I then cycled over to one of two Windows Server 2003 instances Id installed on my test system. The first Windows Server 2003 instance Id installed was a preconfigured virtual instance that I acquired through Microsofts Run IT on a Virtual Hard Disk program, under which the firm offers up various server products for evaluation in Microsofts VHD format.

According to a Microsoft official, this CTP release of Viridian does not support direct import of VHD-formatted instances, but I was able to create a virtual machine configuration and connect the pre-made virtual hard drive to my new instance.

This was a quick route to installation, but I encountered a problem when I attempted to install Viridians virtual drivers on the system, which had been configured with the virtual drivers pack for Microsofts Virtual PC product. The system instructed me to first uninstall the earlier driver set before loading the new drivers, but the uninstaller for the Virtual PC drivers—sensing that it was running on the wrong sort of host—refused to run at all.

I had better luck with a Windows Server 2003 instance that Id installed from a standard product disk image. On this instance, Viridians driver set agreed to install, and I watched as a handful of previously unrecognized pieces of virtual hardware were automatically recognized and installed by the system. From there, my Windows Server 2003 instance performed normally, with full network connectivity.

eWEEK Labs Executive Editor Jason Brooks can be reached at


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