Virtual Machines, real benefits
Published January 16, 2008 at 2:06 pm · Filed under Features
In the second article in his series on datacentres, Eddie Partridge explains what virtualisation is and how it is revolutionising datacentres
Virtualisation is not new: it was first introduced in the 1960s to allow partitioning of large, mainframe hardware. However, over time, minicomputers and PCs provided a more efficient, affordable way to distribute processing power, so by the 1980s it was no longer widely employed.
Then, in the 1990s, researchers began to see how virtualisation could solve some of the problems associated with the proliferation of less expensive hardware, including under-utilisation, escalating management costs and vulnerability.
Today, virtualisation is once again at the forefront of IT management, helping businesses with scalability, security and management of their global IT infrastructure; removing hardware complexity; and enabling the safe, efficient deployment of new services.
Virtualisation is an abstraction layer that decouples the physical hardware from the operating system to deliver greater IT resource utilisation and flexibility. It allows multiple virtual machines, with heterogeneous operating systems to run in isolation, side-by-side on the same physical machine.
Each virtual machine has its own set of hardware (e.g., RAM, CPU, NIC, etc.) upon which an operating system and applications are loaded. The operating system sees a consistent, normalised set of hardware regardless of the actual physical components.
Virtual machines are encapsulated into files, making it possible to rapidly save, copy and provision a virtual machine. Full systems (fully configured applications, operating systems, BIOS and virtual hardware) can be moved, within seconds, from one physical server to another for zero-downtime maintenance and continuous workload consolidation.
Scalability
Nearly everyone reading this article will know how much we rely on the effective running of servers to store data, centralise resources and provide back up. Typically, as a business grows so does its hardware: the number of workstations increases, data volumes rise and there is more demand for an efficient IT infrastructure.
The normal response to IT growth is to add extra components or acquire more rack space within a datacentre: virtualisation provides a much more sustainable solution.
By adopting virtualisation software, there is no limit to how big a business can grow. Servers can be consolidated into virtual machines that can be moved or copied as single files.
This means that a single physical system can support multiple applications and operating systems, giving businesses complete flexibility to either scale up or down their IT infrastructure without spending extra money.
It’s not just servers that benefit from this new methodology; tape libraries and data storage have also been revolutionised through virtualisation, again resulting in lower IT costs and improved security.
Cost-effectiveness
By enabling businesses to make better use of hardware resources, virtualisation delivers significant cost savings. It reduces the need for hardware, which leads to lower operational costs (by up to 60%) through reduced power and cooling requirements and lower IT management costs, as less time needs to be spent on maintenance, monitoring and configuration.
Security
Virtual machine technology helps provide a solution to IT security, too. First, it can isolate applications that are run on the same machine, and secondly, you can add in monitoring and filtering software to restrict what virtual machines can do, which is more difficult to do when applications are running on the bare iron.
This is such a useful capability that virtual machine technology is even being considered in the consumer sector to improve security on home computers, for example by separating where you do your family finances from where your kids run their games.
In addition, virtual machines remain completely unaffected by natural or man-made disasters, such as fire, floods and power cuts. Instead of creating several physical datacentres to protect secure data, a bank could now create virtual datacentres to be copied or scaled up accordingly.
High Availability
One of the last points about virtual machine technology is that it simplifies the provision of ‘high availability’. If a host fails and the virtual machine images are on shared storage, you can easily restart the virtual machine on another host. Or, if a host is failing and errors are flagged (e.g. an overheating CPU), you can do live migrates onto another host without affecting the application in any way. One can also do back-ups of the virtual machine to save an image for easy retrieval in the event of a catastrophic failure.
Eddie Partridge is Business Development Director of Latitude UK Ltd, one of the UK’s leading providers of single source power protection and IT infrastructure solutions for IT and Telecom environments.
http://www.latitudeuk.com/ 01793 421 800
