Confused about which technologies to use and how to protect your investment in the long term? Cláudio Rodrigues, CEO at WTSLabs Inc., a Canadian IT consultancy that helps companies design and install virtual desktop infrastructures (VDI), answers some common VDI questions.
I'm already using Microsoft Terminal Services (TS), so why do I need virtual desktops?
Cláudio Rodrigues: Typically, a company first uses TS [or Remote Desktop Services (RDS)] because it has applications it wants end users to access from anywhere. But the missing piece in TS has always been flexibility.
With TS, one server is shared by many people, so each user is "locked down," and end users have restricted access to local resources. With VDI, each end user gets his or her own OS, resources and applications, and since VDI offerings support devices such as iPads and smartphones, end users have more flexibility.
VDI also eliminates most application-compatibility issues, so many companies move to VDI when they have an application that does not run on TS and cannot be virtualized using something like [Microsoft] App-V or [VMware] Thinstall.
TS or RDS also requires an "always on" connection, so you can't work offline. We now see VDI vendors providing offline support with technologies such as XenClient or MokaFive.
We could go on forever on other features/requirements that may lead you to VDI or TS/RDS.... What VDI offers is closer to a traditional desktop experience than TS. That is a big selling point for some companies. That's not to say VDI is always the right answer, and companies weighing the options should engage a consultant with years of experience with both TS and VDI.
How can anyone be sure that installing VDI today won't introduce challenges that are insurmountable tomorrow?
Rodrigues: With any technology, especially a new one, we can't be sure what will happen down the road.
More on implementing VDI
Microsoft's virtual technologies can simplify desktop management
Desktop virtualization comparison: VDI vs. RDS
Zero clients promise to replace fat clients but have downsides
Prepare and protect user profiles before virtualizing your desktop
Building a XenDesktop virtual architecture requires care
But first, become properly educated so you better understand the potential issues. Do not [adopt VDI] just because everyone is doing it ... they may be adding VDI, but it does not mean the installation is proper or successful.
The more complicated your installation, the more locked into the technology you will be and the more risks you will face.
For example, imagine you deploy VDI but you do not care about linked images, so every virtual desktop gets its own big virtual hard disk. And maybe you also don't care about all the fanciness of layering [with profile management products]. Sure, you will use more disk space, and it will probably be much harder to manage. But if you avoid those products, you won't lock yourself in to any vendor.
Avoiding lock-in also means trying to use everything that's common between different vendors. For instance, ESX can serve as a host for VMware View, Citrix XenDesktop or Quest vWorkspace. There are also vendor neutral connection brokers that work with any of the most popular hypervisors.
By leveraging common denominators, it is much easier to change vendors if needed.
This was first published in July 2010