Key questions for VDI
I’ve been trying to work through the key questions that need to be answered about VDI by anyone comparing it to the obvious alternatives, these being:
- A laptop
- A physical desktop
- A client side virtual machine, copied or streamed to the PC
- A web application portal
- A server hosted desktop
Whilst I can see use cases where all of the above are great solutions, it’s not immediately obvious how the decision making process should work in the enterprise. To start off here’s a short discussion of the alternatives:
- A laptop’s a great solution for someone who doesn’t want to work a fixed work locations, but rather wants the flexibility to work shoulder to shoulder with a colleague, work in conference rooms, hotels, the back garden etc. Clearly it’s also the only solution for people working with unreliable or no network connection. I see this workstyle being pretty standard for many knowledge workers going forward.
- A physical desktop seems most at threat from VDI, it doesn’t offer any particularly compelling attributes, until you start to think about the future of the desktop. Practically unlimited encrypted storage, low power consumption, support for operating system streaming or iSCSI boot, massive computational capacity. If someone could figure out how to drive real productivity improvements by using all that storage and processing power then we might easily see the desktop swing back into favour. Even if the desktop PC continues to be used pretty much as it is today It’s not unreasonable to consider the desktop as essentially a VDI client, streaming OS, Apps and Environment on demand in a very VDI like way but just without all of that server and storage infrastructure.
- I’ve used client side virtual PCs for years, but I wouldn’t want to do all my work on one. My gut feel is that this will change by 2009 when we will see client side hypervisors readily available and these hosting one or more personal VMs and an enterprise VM thats either streamed to the client, along with streamed apps and environment or just managed as if it were a physical PC, just easier to fix.
- A web application portal is my favourite way to get at all the “enterprise” applications that I use. I have no desire to go back to using an enterprise desktop. Just give me my personal laptop and Internet access and I’m away. CSC provides me with a portal that fronts expenses, procurement, email, collaborative services etc, and I get a backup solution for my PC that provides an Internet accessible web site for me to access/recover all my documents in the event of a hardware failure or loss/theft of my laptop.
- A server hosted desktop, most often XenApp provides a locked down environment that meets the needs of many users, and at a price point that VDI can’t reach. Of course for enterprises that just want to publish applications, it provides a great solution for that too.
Ok after rambling through the alternatives I think I’m ready with my list of key questions:
- Do you need a solution that costs less than the money you will save by replacing desktop PCs? If yes then it’s unlikely that VDI is for you unless the desktop PCs are particularly difficult to support, like those in remote branch offices or home locations. The marginal saving of removing a PC is pretty low when automated tools are used for management.
- Do your users really want a desktop? Lots of users who are using a PC as their client device don’t want another desktop, they just want the applications published to them and integrated into their desktop experience. Microsoft recently ran a trial of their Server 2008 product which offers secure Internet access to applications with “seamless windows” and a full published desktop. Most users just wanted to use seamless applications. As I explained above in CSC we just publish web applications. As consumerization takes hold expect lots of users to prefer to use their own PC for access and look to the enterprise just for the apps they need. Of course publishing a full desktop costs more, but it does offer a more secure environment and a more controlled end to end user experience.
- Do you really want windows applications?, if your users needs are simple – and many people looking at VDI keep saying all my users need is email and Office – then perhaps all they really need is a good web email and a well integrated web office suite, and that’s way cheaper than any virtual desktop solution.
- Do you already have a well managed desktop environment in place? if you do it’s fairly easy to just deploy a VDI environment to essentially just “provision virtual machines” from that point onwards you might well find it’s cheaper to manage them like every other PC on your network. You can’t do this with XenApp so unless you already have a well managed XenApp environment in place you will probably find that XenApps infrastructure cost advantage is written off by increased OS and Application management costs.
- Do your users need to personalise their desktop? lots of people seem to think that users want VDI because they want to “personalise” their desktop. Well by personalise most people mean installing applications and many enterprises frown on that. It might be better to provide two environments, one that’s locked down and includes enterprise applications and another that’s essentially personal. This is expensive if you use VDI to provide both of these, or use VDI for one and XenApp for the other, but its not too bad if you provide your users with an allowance to go buy their own laptop and then provide them with VDI, a client side VM, XenApp or a web portal.
- What are your availability needs? An office full of desktops and laptops can offer a very high level of aggregate availability (for example 95% of an offices PCs might reasonably be available 99.999% of the time) but a VDI or Server hosted desktop environment won’t deliver this level of availability to the desk without a lot of investment. Not many people need this level of availability, but if you do it’s an important consideration.
- When does VDI make sense? Even if VDI isn’t the right solution today, its going to get cheaper – of course PC’s are going to get cheaper – or at least use less power – and more secure and easier to manage as well.
Ok so I’ve rambled on a bit more, if you answered the questions above and still want VDI it’s likely that you have a lot of expensive desktop PCs to replace and/or you want to increase security, flexibility and agility and you want to do it now.
Time for me to offer up what I thinks going to happen:
- A lot more laptops, I think perhaps 30-50% in many enterprises
- Initially a lot of edge cases where VDI makes really good sense, you might say “the places that traditional desktops and laptops find hard to reach”
- Some enterprises that have very large desktop user populations today, who don’t have a rich mobility requirement, but do have a large and complex legacy application portfolio will be tempted to move to VDI now
- Users who do get VDI will get a smartphone as well, or at least get access to email, presence, IM etc on their own smartphones. perhaps the smartphone will have a bunch of virtualized client applications on its USB drive that can be accessed from any PC, including the VDI client software
- Within a year VDI costs will have fallen a bit, but not enough. Desktop PC TCO will have fallen as well and security and manageability will have increased making VDI more expensive again, but with fewer advantages.
- The app streaming, environment streaming and OS streaming infrastructure that represents the most sophisticated VDI implementations today, will support desktop PCs and ultimately portables as well. At this point client device choice matters a lot less, and of course it’s then not either or. It’s simply a matter of right device, anytime, any place. if I’m a laptop user but I need to quickly access a large file I can run up a VDI environment on demand, laptop gets stolen no problem, just spin up a VDI session for a week and then stream everything back to my new laptop when it arrives.
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It’s almost a year since I made this post and I’ve learned a bit since then. The key additions being:
1. Whilst there are lots of alternatives presented in my post, one thing the physical desktop PC had going for it was it was one technology that met most needs. VDI is maturing into that one approach that meets most peoples needs with only limited compromise.
2. I still think the best route for enterprises is to build an infrastructure for OS streaming, App Streaming, Configuration Streaming and User Personalisation. This infrastructure can be used for VDI and Terminal Services today and for the next generation of physical desktops and client side virtual machines tomorrow
3. Take care to select vendors for this infrastructure that share your vision of one infrastructure to support many different desktop delivery technologies
4. When you deploy VDI, make sure you don’t think of the Infrastructure as VDI specific
5. Don’t rush into large scale change unless you need to, there’s plenty of opportunity to deliver business value solving the hard problems of desktop and application delivery (branches, offshore, customers and suppliers) right now