Implementing virtualisation through Hyper-V

Virtualisation is the first step towards the cloud and recent changes to Windows Server 2012 make it an easier move

How can server virtualisation provide huge benefits to organisations of any size?

With recent advances even resource-intensive services such as SQL can run in a virtual environment with almost the same level of performance as running directly on a physical server.  This means most are likely to be candidates for virtualisation.  But what do you gain by doing this?

Cost savings are often the driving force behind changes in infrastructure and virtualisation helps here.  Take the example of a network running three ageing physical servers.  You can either buy three more servers to replace these, or buy one server and run three virtual servers on it.  Often physical servers don’t use their resources fully and a low-cost server may be able to run all three servers; a single server is also likely to draw less power than three separate servers.

Cost savings are often the driving force behind changes in infrastructure and virtualisation helps here

Virtualisation provides a flexible framework that can meet the ever-changing needs of a business.  Providing more memory or disk space to a virtual server can be done with a few clicks of the mouse.  And once all the available resources of your servers have been used, simply buy another one and move some of the virtual servers across to it; this can all be done without even needing to shut the virtual servers down. 

If at a later stage you want to add shared storage, then you can move the virtual servers across to that without any downtime.  When you compare this to the complexities of moving services between physical servers, it’s not hard to see why virtualisation is a much better solution.

In an ideal world each server would run one or at most a small set of services.  So your web server wouldn’t also double up as a file, SQL and Remote Desktop server.  With a limited number of physical servers this can become impossible.  A large number of applications on a server increase the chance of conflicts occurring and also make troubleshooting more complex. 

Contrast this with virtual servers each providing a single service or small set of services; conflicts are less likely to occur and individual servers can be rebooted if required.  So if your web server is about to crash you can reboot that on its own, leaving the other services available.

The transition to virtualisation doesn’t need to be a complex one and you can start off with just a single server.  With a variety of physical-to-virtual (P2V) services available, you can even take an image of a live physical server and turn that into a virtual server. 

Hyper-V in Windows Server 2012
Microsoft has enhanced Hyper-V and has made it more attractive for organisations who wish to introduce virtualisation. One of the significant improvements is to Live Migration. As the name suggests, this allows virtual servers to be moved between physical hosts while all the services continue to run.  In previous versions of Hyper-V Live Migration only worked if the virtual server was located on shared storage such as an iSCSI or Fibre Channel array.  Now virtual servers can be moved without shared storage, so you can benefit from Live Migrations without the need to invest in expensive additional hardware.