Microsoft Virtual Server 2005 Release 2 carries out its virtualization chores about as well as competing products from VMware. However, Microsofts server virtualization solution still lags in certain key areas most notably, support for host and guest operating systems. Click here to read eWEEK Labs review of VMware Workstation 5.5.Virtual Server 2005 R2 Standard Edition costs $99 and supports between one and four physical processors. For more than four processors (the upper limit is as many processors as the version of Windows youre running them on will support), theres an Enterprise Edition that costs $199. Until very recently, Virtual Servers low cost was arguably its biggest advantage over the analogous product from VMware, GSX Server, which costs between $1,400 and $2,800 per server. However, VMware recently announced that its follow-on to GSX Server, called VMware Server, will be available for free. (VMware Server is available now in beta; the final release is expected before the second half of this year.) How will virtualization change the infrastructure landscape? Click here to read the Labs analysis. We tested Virtual Server on a white-box system outfitted with an Advanced Micro Devices 2.2GHz Athlon 64 processor, 1GB of RAM and Windows Server 2003 R2 Enterprise Edition. We tested with the 32-bit version of Windows. Theres also a Virtual Server edition available for Windows x64, but, at this point, Virtual Server 2005 does not support 64-bit guest operating systems. Virtual Server will run on basically any x86 hardware, although Microsoft suggests at least a 1GHz processor. The most important hardware requirement for Virtual Server is RAM. You need enough RAM for each concurrently running machine instance; the more RAM available, the better. Virtual Server can take advantage of multiple processors but does not expose multiple processors to its guest instances. Virtual Server is limited to Windows as a host operating system, and only Windows operating systems are officially supported. However, most x86-based operating systems should run with Virtual Server. In our tests, for instance, we managed to install Software in the Public Interests Debian 3.1 on Virtual Server without any trouble. Virtual Server 2005 R2 sports a Web interface for administration from which we could create, monitor and modify the VM instances we created. We were able to access the Web management interface from any machine in our network, using Active Directory to keep track of authentication. We didnt configure the administration site to use SSL (Secure Sockets Layer) encryption in our tests, but Virtual Server does offer that option. While we appreciated the flexibility of the Web console, we found the interface limiting compared with the richer, thick-client interface of Microsofts desktop-oriented virtualization product, Virtual PC 2004, or of VMwares Workstation interface. We had to use Microsofts Internet Explorer to remotely control our instances, but the Mozilla Foundations Firefox worked fine for most other administration tasks. We managed to control our test instances from Linux using Windows Remote Desktop and the Linux application desktop. Virtual Server didnt offer us a whole lot in the way of system diagnostics. We could view small CPU utilization charts from the admin site, as well as review event log entries related to Virtual Server itself. To peer more deeply into our instances, however, we had to use standard monitoring tools. We were impressed with Virtual Servers capacity for controlling allocation of system resources among our guest instances. We could devote a particular processor to one of our VMs, as well as reserve or cap processor capacity available to particular instances by percentage. More simply, we could assign each of our instances with a relative weight, ensuring that our more resource-needy instances received priority. One of the great things about deploying or testing applications in virtualized instances is the ease with which virtualization products let administrators create snapshots of the instances for rolling back unfortunate changes or for branching through separate deployment options. Through its handling of the virtual disk images on which the product stores its guest instances, Virtual Server offered us plenty of flexibility in carrying out these operations. We could create the virtual disks for our instances along with an "undo disk" that let us, upon pausing or shutting down an instance, merge whatever changes wed made to the instance or discard them. We could create disks that expanded as we added data to them, create disks with space preallocated or create linked disk scenarios, with a parent disk and linked child disks that contained only the differences from the parent. Virtual Server doesnt include functionality specific to provisioning virtual instances, but Virtual Server guest instances do support PXE (preboot execution environment) booting, which lets you provision VMs in the same way you provision regular systems. Microsoft also offers a tool for migrating operating system instances from physical hardware to virtual instances (at www.microsoft. com/windowsserversystem/virtualserver/evaluation/vsmt.mspx). Virtual Server exposes several COM (Component Object Model) interfaces for scripting Virtual Server functions, but we did not delve into this. Next page: Evaluation Shortlist: Related Products.
With that said, Virtual Server is relatively inexpensive, and it offers a solid option for sites that wish to consolidate individual Windows servers with modest resource requirements.