Virtualisation is the process of partitioning servers so that they act as multiple servers, allowing the expansion of IT resources without incurring the costs of physically expanding infrastructure.

So in effect, for example, instead of having one physical machine running one operating system, with server virtualisation, you would have one physical machine running multiple copies of an operating system.

The main benefit of virtualisation is that it can cut a business' IT costs. For instance, a business with multiple servers could use server virtualisation to eliminate x number of those physical servers, freeing up space and cutting down on the energy, maintenance and security costs related to their physical IT plant.

There are many types of virtualisation- server, network, storage, and more.

At a time when businesses are under pressure to find ways to reduce costs, virtualisation software is one relatively easy step in the right direction. It lets organisations optimise their IT infrastructure through hardware consolidation, enabling one server to run multiple applications from a single machine . You can even run multiple operating systems on a single server.

Most servers are underutilised and run well below their processing capacity yet still consume power and require cooling. This inherent inefficiency is compounded with the ad-hoc purchase of hardware as businesses roll out new applications creating a sprawl of servers in over-crowded data centres.

Virtualisation lets you rationalise the environment and run six or seven servers on one single box.

Server virtualisation inserts a layer of abstraction between the physical server hardware and the software that runs on the server. The physical machine is translated into one or more virtual machines (VMs). Each VM runs its own operating system and applications, and each utilizes some allocated portion of the server's processing resources such as CPU, memory, network access and storage I/O.

The primary advantage with server virtualisation is improved server utilization. Rather than deploying numerous servers that may not be fully utilised, server virtualisation allows multiple VMs to operate on the same physical platform.

The theory behind network virtualization is to take many of the traditional client/server based services and put them "on the network". Network virtualisation is a method of combining the available resources in a network by splitting up the available bandwidth into channels, each of which is independent from the others, and each of which can be assigned (or reassigned) to a particular server or device in real time. Each channel is independently secured. Every subscriber has shared access to all the resources on the network from a single computer.

Network virtualisation is intended to optimise network speed, reliability, flexibility, scalability, and security. Network virtualisation is said to be especially effective in networks that experience sudden, large, and unforeseen surges in usage.

Storage Virtualisation is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in a storage area network (SAN). The management of storage devices can be tedious and time-consuming. Storage virtualisation helps the storage administrator perform the tasks of backup, archiving, and recovery more easily, and in less time, by disguising the actual complexity of the SAN.

Users can implement Storage Virtualisation with software applications or by using hardware and software hybrid appliances. The technology can be placed on different levels of a storage area network.
 

As well as consolidating the day-to-day environment, virtualisation is a boon for business continuity and disaster recovery. You can replicate and backup your entire environment to a single offsite box.

From an IT perspective it is much easier to manage. Hyper-V comes with integrated management tools that let you run both physical and virtual resources, enabling you to stay on top of an agile and dynamic environment.

Another advantage is that new desktop images can quickly be configured and rolled out to users. For developers and IT professionals it also provides a rich and varied test environment that can be quickly configured from a single server.

Finally, virtualisation is environmentally friendly. Cutting down on power consumption in the data centre will benefit any company looking at green issues as part of its corporate social responsibility agenda.

Like cloud computing, the basic theory is that having it 'out there', where someone else hosts and manages it, saves you time and money in-house.

At a time when businesses are under pressure to find ways to reduce costs, virtualisation software is one relatively easy step in the right direction. It lets organisations optimise their IT infrastructure through hardware consolidation, enabling one server to run multiple applications from a single machine . You can even run multiple operating systems on a single server.

Most servers are underutilised and run well below their processing capacity yet still consume power and require cooling. This inherent inefficiency is compounded with the ad-hoc purchase of hardware as businesses roll out new applications creating a sprawl of servers in over-crowded data centres.

Virtualisation lets you rationalise the environment and run six or seven servers on one single box.

Earlier this year it launched Hyper-V as part of Windows Server 2008. Technology that helps consolidate server racks in large organisations was always going to be welcome, but Hyper-V gives smaller firms with just three or four servers a viable business case for virtualisation. Not only is Hyper-V less expensive than its competitors, it provides more tools to make easier work of converting physical servers into virtual machines, and it can be installed straight away with Windows Server 2008.

As well as consolidating the day-to-day environment, virtualisation is a boon for business continuity and disaster recovery. You can replicate and backup your entire environment to a single offsite box.

From an IT perspective it is much easier to manage. Hyper-V comes with integrated management tools that let you run both physical and virtual resources, enabling you to stay on top of an agile and dynamic environment.

Another advantage is that new desktop images can quickly be configured and rolled out to users. For developers and IT professionals it also provides a rich and varied test environment that can be quickly configured from a single server.

Finally, virtualisation is environmentally friendly. Cutting down on power consumption in the data centre will benefit any company looking at green issues as part of its corporate social responsibility agenda.