Over the last couple of years virtualisation has extended beyone the enterprise and entered the awareness of SME’s. I say ‘the awareness’ as I don’t believe many SME’s outside the IT sector actually utilise virtualisation software in their day-to-day activites. This is a shame because I believe that the are a number of advantages that virtualisation can bring to the growing company.
First of all, a quick overview of virtualisation. What I am referring to here is the ability to create one or more software environments on a hardware platform. In essence, run more than one operating system (all the same or a variety thereof) on a single PC or server. There are a number of alternatives on the market, the generally acknowledged best of which is VMWare’s range. However, Microsoft has also bought into the market and caused a bit of a shake-up when they started offering the PC and server products for free. VMWare quickly followed suit, creating a great opportunity for SME’s to get themselves on the virtualisation ladder without any initial financial outlay. For a full list of virtualisation services offerings, have a look here.
The most common use of virtualisation is to run a number of virtual servers on one physical server. Why ? Well a typical server is actually only utilised between 10% and 20% of it’s potential maximum. Obviously, therefore, there is scope for utilising that other 80%-plus. In the past, many people have run software that uses their spare CPU cycles for community projects, such as SETI@home or Cancer research. This is commonly refferred to as Grid Computing. And if you’re happy to donate computing resources like that, then that’s fine. But maybe you should consider using them as effectively as you can first, and then donating what’s left?
Disclaimer time. I have looked most extensively at VMWare, so will talk about their products here, but that does not mean that other solutions will not do the same thing, as always it’s worth spending a bit of time and effort looking at the alternatives for yourself.
So how can you utilise virtualisation within a company that doesn’t span continents ? Well, if you’ve got even a single server then it’s worth considering. With a single physical server, you are probably running all sorts of services that, in a larger organisation, would warrent separate servers. You are probably using it as a file server, print server, email server, domain controller and directory services. You might be using it as a web proxy, a firewall, or any of a number of different things. And wht happens if any one of those services causes the server to crash, or require a restart? You got it, everything is unavailable until the whole shebang is back up again.
Traditionally, the means of separating out these services has been to utilise any piece of hardware that’s available to run them. Typically, a domain controller or a print server or a file server doesn’t need to be a powerful box, so the PC that can’t run MS Office any more is pressed into service as a server. Now think about this. Your company is using a desktop PC that’s probably 4 or 5 years old minimum as a core part of the network infrastructure. It’s designed to be a reasonably reliable workhorse for your admin people, but disposable. If it stops working, the cheapest option is to chuck it away and buy a new one for £200 or £300. You scared yet? You should be!
This is where virtualisation comes in. Invest instead in a reasonably powerful server. Stick it in an air-conditioned environment. Haven’t got one, rent some space in a data centre, or rent a server from a hosting provider. Install a reliable, secure operating system, remember you can get Linux for free. Install your free verion of you favourite virtualsation product (VMWare server fits the bill). Install your guest operating systems – you might need Windows for your domain controller and directory services, but why not use Linux for file serving and print serving? And voila, you have a much more stable environment.
There is a lot more to consider in this scenario, obviously, and there are many other reasons why you might want to consider virtual machines. I will touch on these in future blog entries. Stay tuned!
November 14, 2006 at 11:08 pm
[...] Continuing on from my previous post on virtualisation, there is another relatively easy, but very effective way of using virtual machines in your organisation. But first, let me ask you a question. [...]
December 5, 2006 at 3:19 pm
Hello
I was very interested in the article you wrote about virtualisation. Indeed, it would appear that it certainly solves a certain “testing environment gap” however I have a question I would like to ask:
If you run a series of virtual servers on an actual physical server, what happens to the virtual servers if you change the date e.g. roll the date forward, of the physical server? Does the date for every virtual server change too or do they behave independently?
Thanks in advance
Chris
December 5, 2006 at 4:11 pm
Chris,
Glad you enjoyed the article
You raise a very good point, and I can only speak for VMWare’s capabilities in this area, although I would be surprised if the other major vendors sis not have similar functionality.
The short answer is…not necessarily. You can actually choose what kind of behaviour you want to have happen. With VMWare guest OS’s, you would normally install a set of VMWare Tools that add extra fnctionality to your OS. One of the options with these tools is to enable synchronisation of the date between the host and guest OS’s (once a minute, if memory serves correctly). But it is optional, so you could just leave the guest OS to sort itself out.
Bear in mind, though, that the guest OS does not have direct access to the BIOS and, in a testing situation, is likely to be re-booted, suspended, have snapshots taken of it, etc, etc. So a good process around verify the date is as you want and expect it to be is certainly desirable.