I spent yesterday at the Hampshire ICT conference presenting on virtualisation on behalf of one of our partners, Medhurst IT. What made my session here unusual and interesting was the audience; there were quite a few teachers who wanted make sense of virtualisation, both for themselves and to explain it to their pupils studying ICT. I thought it would be good to share this as there are still many people who don’t know too much about the topic.
The top priority for IT departments in this uncertain world is consolidation i.e. getting more done with less. Virtualisation is seen as synonymous with this but it isn’t necessarily so unless it’s done right. Before I get into that what is virtualisation anyway? It’s the business of detaching what we are doing on a physical computer (be it client or server) so that we can move that work to other computers at will. We can virtualise a number of things:
- We can virtualise what our servers are doing
- We can virtualise what the client does and allied but separate form this ..
- We can virtualsie the desktop our users are using and at a lower level of detail ..
- We can virtualise an individual application be something simple like Adobe Reader to a full on application like Visual Studio,
Server Virtualisation enables lots of virtual servers to exist on one real or physical server and has been around for year with mainframes, and is no more mainstream for windows and linux servers.
Terminal Services or Remote Desktop Services as it now called has long been the traditional method to virtualise a desktop for a client to use. This can also be used with thin client devices in place of full fat PCs.
That leaves the two newer forms of virtualisation Virtualised Desktop Infrastructure (VDI), and Application virtualisation.
VDI is simply the business of using server virtualisation technology to provision a virtual machine running a client operating system for each of users. I can see a few niche use case where this might offer more flexibility and capabilities to certain types of users but in reality remote desktop services can cover a lot of the same use cases and needs less computing power to provide the same services as VDI.
Application virtualisation allows an IT Pro to identify a bunch of users or computers that need a piece of software and then streams this down forma server when required. The clever bit is that it doesn’t actually install and allows multiple versions of things like excel to happily co-exist. Central control also allows best use and control of limited licenses of expensive software e.g. Visual Studio Team System or Adobe CS5. However this technology means that the software is running on the client machine. The other way provide an application to a client without installing it is to use remote desktop technology to just provide the application. However you need to be permanently connected to the network to use any remote desktop technology, whereas with application virtualisation you only need to be connected to download the application.
However none of these approaches to virtualisation will achieve any real savings without really good management, any more than an eco friendly car will save carbon unless driven carefully. While running six virtual servers on one physical server will save some power and rack space, each of these virtual servers still has to be managed (patched updated, audited etc.) so you can’t downsize the IT team at all just because you have done this.
To really get the benefit of using virtualisation you need solid management tools to manage both the physical and virtual servers from one screen. These tools aren’t just about patching and updates (though that’s essential) it’s about performance monitoring to ensure you are getting the most from the data centre, and to have the information to prevent problems rather than having unplanned downtime.
Microsoft’s approach to virtualisation is odd in that you don’t actually license any of it , rather it’s built in to operating system or in the case of application virtualisation you get as free extra when you have software assurance. However Microsoft does have paid for products for managing your virtual infrastructure – System Center. One other free thing you will need to get you started is the Microsoft Assessment and Planning Toolkit which will identify what Microsoft products (versions service packs etc.) you have so you have a baseline to plan your virtualisation strategy
A quick scan of the web using your favourite search provider will no doubt give you a bunch of resources from Microsoft’s partners and competitors on virtualisation but if you want to know more about Microsoft’s approach to virtualisation then follow these links: