Everyone knows that more and more people are thinking about VDI, or at least they’re talking about VDI. And most of these people don’t really know what they’re talking about, what they really want and what they need. There are more usecases, solutions, alternatives which might be better for most of them.
In this article i’m talking about ‘hosted virtual desktops’, the way most people see VDI. The desktop is a virtual machine running on a hypervisor in the datacenter.
Yesterday I attended a presentation where VMware was talking about VMware View, there product for VDI implementations. In this presentation one of the key-features of VMware View was there ESX plaform, and all the ‘fancy’ features this hypervisor has. And with ‘fancy’ features I mean features like VMotion, High Availability, DRS and Fault Tolerance.
These are all great features and very usefull, in enterprise environments, for servers. In smaller environments these features aren’t necessary or even needed. In fact, in most enterprise environments not all features are really required, there used because “we can”.
But are those features necessary or even usefull for workstations? At first I didn’t see the purpose of all these features. Do you want a running workstation to move from one ESX/HyperV/XenServer to another? Is High Availability or Faul Tolerance needed? Moving a running workstations costs performance, requires a big infrastructure and a (more) expensive license. And do you really want a workstation to keep on running, 24×7? Not really, right?
In fact, unlike a server, most workstation just won’t work after days, weeks or maybe months. There’s always an application that’s isn’t well written en is abuseing memory in one way or another, isn’t closing handles right and increases threads like it’s free air. (Okay, my laptop runs fine altough Ihibernate all the time.)
Most workstations are used by task workers, sometimes by knowledge workers and of course some are used by “special” users, like your boss. So most workstations are ‘just’ virtual machines. When something goes wrong and the user calls the helpdesk the advice would be to ‘restart the computer and everything will work again’. Yes, this happens everywhere.
But what would you do if the hardware is broken, or needs service. You’ll have to ask the user to switch location, fix the problem on location and return again. Which means the technician needs to communicate with the user, maybe even your boss.
With VDI this won’t happen. If the client device fails you just replace it, everyone could do this. And if you have a hardware failure you restart the machine on another server, this could be done within minutes (no engineer is that fast on location!).
And if you want to service a server, you could just move the (running) VM to another server. No-one even knows the IT department is working hard (hey, is this helping us?).
Another ‘issue’ which is inevitably in most environments is that most computers are either over-powered or under-powered. When you buy a new machine it has just way too much CPU and way too much memory, you really don’t need all that. But eventually you do need it, applications need more and more, so it’s a ‘good’ decision. On the other side are the companies who doesn’t replace there machines on time and expect them to survive for 5 years. And if they do, they – are – just -tooo sloowwwwww….
This is where VDI could ‘help’ you. And you may notice i say ‘help’, with quotes. VDI in combination with a hypervisor which has a DRS (dynamic resource scheduling) solution can help you utilize more of you’re CPU and memory, and so be more efficient. When you need more power you just add another server, and vice versa. Brilliant, right?
I haven’t decided yet whether all these features really are needed. I just came up with these two possible use-cases, but only because ‘we can’ not because need it.
So, wrapping this up. Are you thinking about VDI, virtualizing desktops or just redesigning you’re desktop strategy. Think about what you need, then how you want to achieve this and eventually about the products that can fullfill you’re needs. I can write dozens of articles about products and there usefull or cool features, but please ask me what to do before you ‘do VDI’.
Ingmar Verheij
English 
Nederlands