Virtualisation in the real world

01 Oct 2009 View Comments
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Allan Wardhaugh
Wardhaugh: Do not assume you can introduce virtualisation without your software vendor's consent

Every IT leader knows that the projected cost savings from the introduction of a virtualised environment are significant. Implementing virtualisation, in whatever form, is often stated to be a “no-brainer” from a cost perspective.

Further reading

In reality, a significant part of virtualisation project costs is often overlooked ­ – the software licensing. It is surprising how many companies go down the virtualisation route without first checking exactly what the impact of doing so will be on their existing software licensing. These costs can be considerable. They need to be factored into the business case for any virtualisation project.

If the licensing position is not checked before implementing a virtualised system, a company may find itself in breach of many of its business-critical software licences. That could lead to a company finding itself in court being sued for copyright infringement and/or subject to a court order preventing it continuing to use that software.

Would a software vendor go that far? In most cases the answer is probably no, due to vendors wishing to have continuing, revenue-generating relationships with the organisation concerned. However, the threat of such action is certainly a useful negotiating tool when vendors are considering just how much money they want from you to “resolve” any licensing issues.

Current licensing models
Software vendors have been licensing software to companies over the years using various models depending on factors such as the type of software concerned; where it is used; who is using it and the environment in which it works.

In the early days, vendors licensed software use on very restrictive terms –­ for example, software was to be used only on, say, a particular machine, at a particular location or by specified individuals. The reason for this, allegedly, was to make sure they could support it properly. Cynics viewed these restrictions as a way of getting more money out of licensees if they bought new hardware or moved premises. That type of licensing is very unusual now.

Current licensing models vary from vendor to vendor and can be complex. Use may be limited to a particular machine type, to one “instance”, or to certain categories of users, for example, company employees but not to outsourced service providers. Licensing terms often also vary from version to version even where the supplier remains the same.

Your existing software licences almost certainly do not take account of running in a virtual environment –­ that is, across a number of physical machines and in a number of virtual ones. Although the licensing models are myriad, generally, there are restrictions on the number of copies of the relevant software a company may use. These restrictions are often also tied to the machines on which they run.

Why does virtualisation change things?
Server virtualisation involves the creation of a software implementation of a whole platform, known as a “virtual machine”. This is made possible by an additional software layer, the hypervisor, which allows multiple virtual machines to be run on the same server. This physical-to-virtual transformation unlocks the potential of under-used processing power, leading to massive efficiencies. One PC can, in a virtualised environment, do the job of many. This also cuts the number of servers needed and operational costs such as air conditioning and maintenance.

Application virtualisation operates at a higher level by separating an application from the operating system on which it runs. This allows applications to be hosted in a cloud environment and accessed as a virtual application on your desktop. Application virtualisation technology also allows applications to work across different operating systems without the need for rewriting code.

Desktop virtualisation allows “virtual” desktop machines to be stored in the servers in your datacentre. This reverses the trend that has, until now, seen thin clients go out of fashion in favour of fully featured PCs. This inevitably will mean less hardware expenditure. Compared to previous models of thin-client computing, services can now be provided from off-site servers across the internet. Users can access their desktop from any location with an internet connection. Virtualisation technology makes it easier to manage user accounts and upgrades can be rolled out centrally.

One benefit of virtualisation is mobility. Operating systems and applications can be packaged into a virtual machine and moved between computers. Virtualisation has severed the link between a specific piece of hardware and a software application/operating system.

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