Issue 3: No defined desktop virtualization standards
Many different companies have desktop virtualization offerings, but not many of them address the issue of compatibility. Sure, you can use connection broker "A" with any of the major hypervisors, but there is a lack of virtual disk and connection protocol standards. If you're using a Citrix system, then you'll be using independent computing architecture for a connection protocol, whereas if you are using Microsoft's connection broker, you will use Remote Desktop Protocol. I support companies that want to make things work better, but when I put on my enterprise hat, I want to avoid the headache of figuring out compatibility when migrating to another technology. Because there are no real standards for desktop virtualization, your environment can end up being more complex than you'd like.
Issue 4: Proper monitoring and management of the VDI
The amount of management needed for desktops really doesn't change too much when you go from a physical environment to a virtualized one. But how you manage the environment does need to change in a very big way. After implementing VDI, you are completely dependent on the network and back-end infrastructure to be available. If the network or storage area network (SAN) is unavailable, then the desktops will be unavailable. The organization could then lose a serious amount of money because of a decline in worker productivity and possibly a decline in sales or delivery of sales. Spend a significant amount of time planning for availability and management of your VDI infrastructure. It is extremely important to have tools in place for monitoring and managing core services prior to implementing VDI.
Issue 5: Receiving immediate return on investment
A popular trend in IT for the past several years is to only implement tools that generate a cost savings and show a decent return on investment. Desktop virtualization isn't the cheapest approach, and it can often be more expensive in the first year of implementation. In the case of VDI, you need to purchase licensing, servers, SAN disks and maybe thin clients. Therefore you might have to spend about the same or even a little more on technology in the first year before seeing cost savings in the long run.
I've primarily focused on VDI because it is the predominant desktop virtualization approach in the enterprise today. These issues are big hurdles. You can overcome them with proper planning and by familiarizing yourself with the various products on the market. There is no single solution that can fix all desktop issues, but virtualization can definitely help you save clients' money and run a more efficient organization.
About the expert
Jason Kappel is an infrastructure architect and virtualization expert at Avanade Inc. He specializes in enterprise infrastructure and data center optimization, virtualization and systems management. He has worked with some of the largest companies in the world to implement green data center solutions and has implemented several multinational server and desktop virtualization systems.