Home : When... and when not to virtualise
When... and when not to virtualise

Approach
Virtualisation makes most sense when it's part of a larger consolidation strategy. Ideally the virtualisation project should consider the IT environment right across the current boundaries of the IT organisation. For example, servers used for quality assurance or testing new applications are by nature candidates for virtualisation. Software developers regularly need to assess different system configurations as part of the development process. Development servers are therefore also prime candidates for virtualisation.

Using this initial approach also avoids touching business critical systems. These should only be considered for virtualisation when sufficient expertise and confidence has been built deploying less sensitive services.

What to virtualise
Applications running on servers that are two years old or more are often suitable candidates. Moving applications from hardware of this age onto currently available multi-core/multi-processor servers will provide similar or superior performance than when hosted on their original hardware.

Any application with a moderate processor, network, disk and memory requirement will yield the best results from virtualisation.

What not to virtualise
The question increasingly becomes why should a server not be virtualised? Not only does virtualisation offer manageability benefits, but it's also now a given - Windows Server 2008 is shipping with a hypervisor, and VMware is already well entrenched in many IT departments. All Unix servers now ship with virtualisation as standard.
With that in mind, some things to consider... don't virtualise:

  • If the server is running an I/O intensive workload, such as a database
  • If you don't have the skills in place to take advantage
  • If you've not done your homework, evaluating business applications and server utilisation

One final thought is the use of virtualisation for disaster recovery, where if one server fails, another can take up the strain. In this case, virtualisation makes sense even if the server is already running efficiently.

Trustco provides a range of virtualisation solutions and advice. Please contact us to discuss your requirements.