Desktop Virtualisation - run many
virtual machines
Danny Bradbury talks to Mark Lomas about how desktop virtualisation has been developed to allow businesses to run many virtual machines.
Mark Lomas
Mark Lomas is a professional IT consultant with 15 years experience. He has a background in IT engineering and technical deployments across a wide range of products and solutions. Mark regularly engages directly with customers as part of his day-to-day involvement in IT project planning and technical design work.
Danny Bradbury
Danny Bradbury is a freelance technology journalist with 20 years' experience. He has written extensively for the Guardian, the Independent, the Financial Times, Backbone Magazine, the National Post and MSN in Canada, amongst numerous tech trade media.
Transcript of Desktop Virtualisation episode with Danny Bradbury and Mark Lomas.
Danny Bradbury: Well hi there I’m Danny Bradbury and welcome to the Icomm technologies pod cast. We are back with mark Lomas, IT consultant for Icomm and today we are going to talk about desktop virtualisation. Now Mark, I have heard about server virtualisation where you get lots of physical servers and turn them into software and run them on one box, but what about desktop virtualisation, what exactly is that and how does it work?
Mark Lomas: Well with desktop virtualisation we are using the same technologies that most systems use for server virtualisation so the same underlying platform, the same software that is available from sort of big vendors out there, Microsoft, VMware, Citrix etc. They all have their own server virtualisation platforms but they have extended them with desktop virtualisation by taking us to a place where we can start to run many, many, many virtual machines all running desktop versions of well, usually things like windows but it could be any desktop operating system Linux or one of the many other alternatives out there and then allowing those to be hooked up to the user through a thin client terminal or a software client so that their desktop experience is being delivered from a server system somewhere.
DB: Okay, it all sounds very advanced, why would I want to do this? Why wouldn’t I just keep my desktop that I know and love down on my PC?
ML: Well many IT environments these days, particularly if they have got quite a lot of desktops to manage face the problem of how to maintain these systems. Many of the companies that we work with will tell us that a lot of time they spend fixing issues is typically spent fixing end user issues on the desk top, going out to users P.C’s fixing the problems and getting things sorted out, figuring out what the user is doing wrong that might be triggering an issue etc so they spend a lot of time trying to get those sort of issues sorted out. One of the techniques that has arised over the years that people have employed in order to try and manage this problem and try and reduce the amount of support issues they have to deal with internally is the concept of imaging a particular PC so that they have a standard image, a standard set up for their PC’s and then redeploy that image if something gets particularly broken or try to lock down the system so that it remains as standard as possible, but no matter what you do there is always a certain amount of drift. There’s always a certain amount of configuration issues that creep in as users try to install their own software or fiddle around with the configuration and you can’t be there to reinstall that image every single day and reset it back to the corporate default so the virtual desktop, that gives you the approach where the images are effectively all stored on the server but they run on the server as well. So rather than the image being deployed out to every user you can have that all running on the server and then the users simply link up to that. Every day you could potentially be re-setting them back to the master image of that virtual machine so that you don’t get this issue of drift creeping in so many users are looking towards virtual desktop infrastructure, VDI as a way to try and maintain the standardised desktop image for their corporate environment so that they can reduce the support issues that they have to deal with on a day to day basis.
DB: I can see how it would take the strain off the support department but what about the actual systems themselves I mean you have servers that must be under incredible strain and then also the network and the storage links as well so could you talk about where the bottle necks are in the system and how you can help to reduce those problems?
ML: The bottle necks in the system primarily come in towards the storage side, these days servers come with multi-core, multi gigahertz processors so there capable of running quite a lot of virtual machines, particularly desktop virtual machines which potentially aren’t running the same big applications or big software that a server virtual machine might run. Network wise, well your only really talking about transferring the screen images and the desktop keyboard and mouse movement back and forth between the users station and the virtual machine, so network band width isn’t quite as heavy as you might think, but server storage that becomes quite critical so when we are looking at for example, hundreds of desk tops that we might be moving towards a world where we are running a virtual desktop system, well if you were just using ordinary PC’s that would be hundreds of desktops with their own individual hard drives. Now you’re trying to pack that all into a server room somewhere so many organisations will look to deploying dedicated storage, a San appliance of some kind which can manage all of the virtual machine images, has plenty of capacity to store them and potentially can get involved in reducing down the amounts of storage space that is required through techniques like thin provisioning or data de-duplication. So looking at the storage is very important, as is making sure that the performance is available in that storage. First thing in the morning for example when everybody is trying to log onto a virtual desktop infrastructure you could find yourself in a situation where you have got hundreds of virtual machines all trying to boot up at the same time, that’s going to put a big strain on the hard disks in the storage array. So you need to make sure that there is enough performance as well as capacity there to cope with that kind of task.
DB: What about the actual management of all this stuff, I mean I can see how support staff again may not have to work quite so hard but presumably managing all these machines, making sure you don’t end up with virtual desktop sprawl and lots of unused machines lying around must be quite tricky in itself, how do you and you know updating the antivirus images on these machine must be tricky so how do you make all that work as well, are there special tools to help you with all that?
ML: Okay well making sure the management of the virtual desktop images is handled as straightforwardly as possible is really something that should be provided through the actual VDI software that you choose to deploy so you will have your virtualisation platform which as I say is usually going to be the same sort of software that would be used for server virtualisation but on top of that we want something that is dedicated to the job of managing these virtual desktop images to sit alongside that, so the VDI solution that you choose to use has got to really include some software to actually help you do that and help you manage all the virtual desktops. So it should really come along and say ok well I’m going to allow you to create a certain number of master images for the different types of users that you’ve got, so each user will be working in their own different departments and each department might need a different configuration in their particular desktop that they will be wanting to log onto so the first thing that you’re going to want to be able to do with the management software is create those master images and then it will be the job of the virtual desktop software to then create copies of all those master images for each of the users that they are going to want to log on and so it’s going to be keeping track of those for you, it’s going to be creating them, deleting them when they’re not needed any more and making sure that the right user gets through to the right desk top alongside that, more recent developments in the area of application virtualisation will allow us to reduce down the number of master images that we have to create so rather than having to create lots of different master images, and install the software into each of them that is required for each department, we can just keep a repository of the software that we need that is then simply slip streamed into each master image as it is cloned off for all of the users that are logging in so that way we don’t need quite so many master images and people to see the software that they need when they log off the desktop so it helps us reduce down the amount of software that we need to think about and reduce down the number of master images that we need to keep track of by ourselves.
DB: Brilliant that’s great. So the bottom line question then Mark is, as a business is doing this going to save me money, I mean on the one hand you’ve got reduced support cost but on the other hand you might have some additional capital expenditure so how’s this all going to balance out and how can I make sure that my bottom line actually benefits from this?
ML: It’s a return on investment question at the end of the day, yes you will be looking at deploying some servers to run these virtual machines, you’ll be looking at deploying some dedicated storage in order to store all the virtual machine data, but at the end of the day your also going to be looking at potentially making some savings in terms of management and support costs but also potentially making savings in terms of traditional areas like power and cooling. If you can move from a model where you are deploying full size, what they call fat client PC’s on peoples desktops to a model where you can be deploying very low power thin clients you could potentially save quite a lot of money there particularly if there is quite a number of desk tops that you are looking to replace. So you can make some big savings in terms of moving from full sized PC’s to thin clients and those thin client devices really are quite low power so compared to a regular PC you could save quite a lot of money across your entire IT environment.
DB: Presumably there is also a functionality benefit here as well; people can start accessing their machines remotely from any device presumably which makes it easier for them to work from home or to work on the road.
ML: Yes, remote access is potentially made a bit easier here, the traditional solutions for remote access were to either give people access to some sort of terminal server that they could log onto but that was quite difficult to manage because terminal server environments you’ve got multiple users all logging onto one server or a group of servers so you’ve got some difficulties there in terms of making sure that people only have access to what they need and making sure that the system is reliable. The other solution used to be to say well we’ll install some remote access gateway and it all links through to your actual PC. So you would have to leave your PC on for 24 hours a day just on the off chance that you might log onto it from home remotely so that would increase costs for most people having to keep PC’s on all the time rather than being able to shut them down at night, or when you’re not needing them and of course there are some networking questions there about how you make sure that you get users through onto the correct PC. With the virtual desktop, everybody’s accessing the virtual desktop whether they are local to the office or remote so it all just comes back to the same point basically, whether your accessing it remotely or locally it all just comes through to the same server so it’s quite easy to get people linked through to their virtual desktop that they need.
DB: Wonderful ok well Mark thanks again for walking us through that, so essentially desktop virtualisation putting all of your desktop machines into software on the server, there can be some savings in terms of support and there can be some enhanced functionality because people can manage or people can access their machines from anywhere but make sure that you take care of things like storage and that you invest enough in your storage and your networks and your CPU power to make this viable. Mark a wonderful conversation, again very useful. Thanks for coming on the podcast.
ML: Thank you very much.
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