Buying parts for a cheap server to experiment with Xen

Virtualization is the future of computing. Virtualizing servers has many benefits which including increased manageability, reduced hardware costs, strengthened security, and others that are outside the scope of this article. Among the array of virtualization solutions Xen stands out as the one I am most interested in pursuing at this time as it is Free/Libre/Open Source Software (FLOSS) and provides the functionality and performance I desire. However, I found myself without a suitable test machine to experiment and test Xen so I decided to see how little I could spend to get something adequate.

Of course, there are some caveats: I didn’t need any disks or optical drives as I have several lying unused in my basement. I could have done without a case but since I knew it was quite likely that I’d be getting a microATX motherboard I figured it would be nice to have a smaller case rather than reuse a larger ATX case. Assuming that I would purchase a motherboard with integrated graphics and networking what I was after was a processor, motherboard, ram, and case.

To understand the processor selection one needs to understand the different ways in which Xen works. Xen was originally introduced using a technique called paravirtualization which allowed for high performance of guest operating systems provided that the guest operating system was modified to function properly in the virtualized environment. In order to use unmodified guest operating systems a new feature was added to Xen to support the hardware assisted virtualization features of newer processors from both AMD and Intel. On AMD processors this features is called AMD-V (formerly Pacifica). On Intel processors this feature is called VT-x (formerly Vanderpool). For this system I want a processor that supports this feature.

The decision between AMD and Intel processors for this system then becomes an easy one. The cheapest AMD processor to support this feature is the Athlon X2 4200+ (Windsor core) at about $75. The cheapest Intel processors (excluding the older Pentium D) to support this feature are the Core 2 Duo E6300, E6320, and E6550 which are all around $175. The Pentium D 920 costs around $100 which is still more expensive than the AMD processor and an older architecture.

For a motherboard I selected the ASUS M2A-VM which has an AMD 690G northbridge and ATI SB600 southbridge. Like many modern motherboards it only has 1 PATA connector. I figured for the test environment that would be fine for 1 hard disk and 1 optical drive and if I ever wanted to use it with RAID I would purchase SATA drives at that point. I went with the cheapest RAM that fit my specifications which was 2x1GB DDR2 800. And finally for a case I selected an inexpensive Foxconn MicroATX mini tower with a 300 watt power supply.

The grand total: $250.

Not bad for a 2.2GHz, dual-core, 64-bit, 2GB RAM system to use for testing Xen.