Both employees and IT go through a lot of changes when you deploy virtual desktop infrastructure. Not only do people's perspectives need to change, but administrators need to deal with a whole slew of new tools and methods for managing virtual desktop use.
One of the key drivers behind VDI implementation is the user experience. You're delivering desktops to on-demand users without limitations on locations or devices. Whether it's through the View Client, Citrix Receiver, Microsoft Remote Desktop Services or something else, VDI provides the opportunity to deliver the right desktop to the right people at the right time. In fact, one big change is a positive one for both the user and IT: fewer downtime issues.
VDI minimizes downtime caused by required desktop maintenance because it's easy for IT to patch and update virtual desktops from a base image. Plus, VDI can improve high availability because a virtual desktop can be accessed from any device. When a device fails, the user can log on to another one and start the same virtual desktop as before -- something that can't be done with physical desktops.
It's not just the user experience that changes. The system administrators who manage a VDI environment will have to change the way they think about desktops too.
So, what changes from an IT perspective when a VDI environment is introduced?
What changes for IT when VDI comes along
Delivery optimization. Introducing VDI means you need to deliver the service -- in the case of VDI, an operating system -- across the network to your users. This is a change from traditional desktop deployment, where the operating system and the desktop hardware are bound to each other, so you need optimization technologies to deliver the right service to your users. That means doing your research when it comes to remote display protocols, to get the best performance out of your virtual desktops.
Touch capabilities. Because you can deliver the desktop to mobile touch-enabled devices too, you might need touch optimization for virtual desktops as well. That means looking into features and tools such as VMware Unity Touch and Citrix Mobility pack. These functionalities will also bring up new things IT will have to get used to, like the use of mobile device controls instead of native Windows controls, keyboard access and different access to the Windows start menu.
Management. Another major change is the way you manage the desktops in your environment. VDI can be persistent and nonpersistent.
Persistent virtual desktops are as close as it gets to a traditional physical desktop. Each user gets his own customizable desktop, so you and they are familiar with the experience. Plus, one of the biggest advantages of persistent VDI is that you can take advantage of the existing management technologies you use for your current desktop implementation.
More VDI implementation resources
Guide to VDI project success
Best practices for a VMware View implementation
What you need before a VDI implementation
Nonpersistent VDI, on the other hand, uses golden image management. You can use existing management tools here too, but working with a golden image will force you into a different mindset. It means that all users get a similar desktop because the image is wiped clean each time they log out; that might make for some unhappy employees.
Some other questions you'll need to address are where to store the persistent data, how to manage user profiles and what to do about monitoring and logging.
Scalability. With physical desktops, where you do one-on-one scaling (one user at a time for one desktop), scaling is fairly easy. VDI adds some more components to the overall infrastructure and depends greatly on storage capacity, so that will affect your ability to scale.
There are three important values for scaling: IOPS, CPU and memory. So how do these change from an administrative perspective? While a regular desktop hard disk delivers just 80-100 IOPS, this becomes more complicated when implementing VDI. Windows (or an application running in Windows) takes as much IOPS as possible, making scaling harder. All vendors deliver calculators for scaling IOPS with default values, but be aware of these values. They can be very different for your environment.
CPU and memory scaling also changes as you can share CPU and memory of a server for multiple desktops, and you can even overcommit when possible to get more users on that same piece of hardware.