Server Virtualisation

Server Virtualisation

In connection with servers the term ‘virtualisation’ comes to the forefront frequently. The term virtualisation can be applied to a wide range of different technologies. Essentially what it means is that virtualising a technology splits the technology from the software. In the idea of Server Virtualisation, it means that multiple environments (Windows, Linux etc…) can be housed in one single piece of physical hardware. This means that you can lower the amount of servers needed. Two Linux servers and one Windows server running on three seperate machines could be virtualised to run on one single box.

How does Virtualisation work?

Server virtualisations work by creating a partition over the physical server. The partition on the physical server can be split into seperate areas that virtual servers can then run on. Creating these partitions splits each virtual server from eachother. The resources from the physical server are then seen as one pool of resources that can be shared equally between the seperate virtual machines. Each of the virtual servers act as their own entity apart from using the pool of resources. This means that if problems arise on one vritual server it will not affect any of the others running on that machine.

Why choose Server Virtualisation?

• Consolidation of your servers: The most obvious advantage and benefit of the use of virtualisation is the ability to consolidate your servers on to a smaller amount of machines. It has been suggested in a report that physical servers generally use about 20 per cent of their capacity. By using virtualisation technology you can increase the capacity and boost hardware utilisation to around 60-80% increasing the ratio of servers to machines to around 3:1 if not higher.
• Lowering your physical boxes: Virtualising your servers decreases the number of physical boxes a company would need. This obviously will help save money with a smaller datacenter and a resulting decrease in cooling and electrical costs.
• Further cost saving: As well as saving on cooling and electrical costs, the most obvious cost saver is saving money on the amount of physical boxes a company would have to purchase. This would lower costs also of your maintenance output.
• Speed and flexibility: Virtualisation allows for the quick and speed creation of different operating system environments. It is easy to run applications alongside new version, migrate applications to new environments and restore systems in malfunction scenarios.
• Easier testing and development: The point runs on from the above, being able to speed up the development and testing process as it is easier to create different operating system environments as well as giving developers the ability to test application performances alongside each other as well as across different operating systems.

Keep in mind whilst choosing Server Virtualisation

• The cost of software and licensing: The big issues that come with virtualisation are the cost of software and licensing. It is easy to create new servers but you have to keep in mind that each one of those servers will require its own seperate software licenses.
• Capacity planning: Planning should be at the forefront of your mind when virtualising machines and to realise the full benefits of it you must match the hardware capabilities with your server requirements. This basically means you need to plan how to fit the greatest number of virtual servers into a physical server without reducing the performance of the individual servers.
• Training: Like any new implementation in an IT environment, virtualisation will require training. Businesses will need to factor the costs of trianing into the overall cost of your virtualisation plan.
• Management: Virtualising servers will lower the amount of physical boxes but they will still require management and maintenance. Many businesses have fallen into the trap that because they are, for example, halving the amount of physical boxes, that means they can half their IT staff, it doesn’t.
• Consolidation Expectations: The ratio into which you consolidate depends on two very important things: how powerful your current boxes are and the demand of your existing applications. For example, if you have powerful physical boxes and your applications under use that power, you can expect a high consolidation rate (more virtual servers onto one box) but if you have a scenario closer to the opposite, you should expect a lower consolidation rate.

Server Virtualisation is a powerful tool that can work well for some businesses but it shouldn’t be seen as an easy cost saving measure.