FoxTalk

Most people in the IT industry have heard of virutalisation, and many undertand how it can benefit their organisation.

There are several virutalisation technologies which operate on X86 hardware. VMWare, Parallels and Microsoft Virtual Server are commercial examples. Open Source technologies include Xen, KVM (now part of the Linux kernel), QEMU and Virtual Box. Each technology has its advantages and disadvantages, and should be assessed against the needs of the organisation.

NetFox has employed the Xen hypervisor for virtualisation. Xen provides hardware assisted full virtualisation (to run unpatched guests like Windows if needed) and para-virtualisation. The para-virtualisation approach utilises a lean OS called a hypervisor to create and control guest operating systems. The total overhead in this approach is typically around 1%, so guests run at near native speeds while wasting very little processing power on running the host OS.

What most people don’t think about is the green factor of virtualisation.

An average server-type machine will consume more than 50% of its full rated power when sitting idle. Power saving technologies such as suspend to RAM and CPU frequency throttling can only go so far in reducing that figure and are often detrimental to performance.

Every watt consumed in the data centre must be matched by at least one watt of cooling. Any savings realised in server power consumption are realised doubly as cooling costs are reduced by the same amount.

Server consolidation also requires less server hardware. This requires less natural resources to produce and less waste to dispose of / recycle at the end of the server lifecycle. This is beneficial because of reduced capital outlay on server hardware, but also in reduced space requirements to house the servers.

Using Xen and Linux hosts NetFox are able to achieve a consolidation ratio of better than 16:1 for most services. Working at these consolidation ratios, NetFox has been able to reduce electricity consumption in our data centre by more than 70%.

This is great for business, but it’s even better for the environment.