It's extremely important that users have a good experience interfacing with their virtual desktops; otherwise, they won't use them.
VDI users do not care about the underlying infrastructure and architecture and all the moving parts IT has to balance. They expect VDI to provide an experience that is at least as good as, if not better than, using a physical desktop. Those are often tough expectations to live up to, but all things considered, it's in IT's best interest to do whatever it can to provide a strong VDI user experience (UX).
The biggest key to ensuring a good end-user experience is to allocate sufficient hardware resources to virtual desktops to prevent performance from suffering. But there is more to providing a good VDI user experience than simply managing hardware resource allocations. Here are some general guidelines that apply to any VDI deployment.
End-user experience monitoring
Although the UX is subjective, it's important to know what's going on within a VDI deployment, and there are a variety of end-user experience monitoring products that focus on different key activities. A UX monitoring tool might, for example, measure the amount of time it takes users to login or for an application to load. There are also tools that measure input responsiveness and graphics quality.
Many of the available UX monitoring tools also notify administrators when certain aspects of the UX drop below pre-established standards. Some tools even attempt to perform automatic remediation or provide the VDI administrator with the information needed to diagnose the problem.
Brian Madden and Gabe Knuth talk from BriForum 2015
Plan for service outages
Outages are rare in the world of physical desktops because each desktop uses dedicated hardware. Furthermore, IT typically sets up redundant networking components such as domain controllers, DNS servers and network switches. That means a resource failure might impact a single user, or possibly a group of users, but nothing short of a power failure will cause a mass service outage.
VDI is different because users' desktops do not have the advantage of decentralized hardware; all of the virtual desktops run on back-end virtualization hosts. Because of this, any infrastructure failure has the potential to affect a large numbers of VDI users. IT departments must have a plan for preventing mass service outages as well as a strategy for coping with any outages that do occur.
The best way to prevent an outage from occurring is to take advantage of redundancy. Every hardware and software component should be redundant, otherwise the failure of a single component could potentially result in a large-scale service disruption.
Of course, even the best plans can fall victim to Murphy's Law, so it's important to have a strategy for service outages. Such a plan might revolve around on-site support or it may involve an IT services support contract. In any case, there needs to be a pre-planned course of action for dealing with outages.
Adopt a "VDI way" of doing things
What this concept really boils down to is being conscious of what the VDI users and administrative staff are doing.
Remember that virtual desktops are really just virtual machines running on top of a hypervisor. Like any other virtual machines, virtual desktops must share the available hardware resources. If those resources run low, performance can suffer, so it is important to use the available hardware resources efficiently.
IT needs to adopt a VDI way of thinking about the various actions that might occur on a virtual desktop and determine whether they are necessary features to include. Actions considered routine on a physical desktop can waste resources on a virtual desktop. One example of this is hard disk defragmentation. Some operating systems perform automated hard disk defragmentation, which can help PC performance, but creates unnecessary storage I/O in a virtual desktop environment.
Some other things that IT might consider limiting include anti-malware scanning, Windows page file usage and Windows background apps. By default, Windows 10 allows background apps to download various types of data. From the user perspective, IT might consider restricting online activities. Playing high-definition YouTube videos, for example, consumes unnecessary resources.
The end-user experience in a VDI deployment is strongly connected to whether IT allocates enough hardware resources to users' virtual desktops, but also to how efficiently IT uses those resources. Administrators can further ensure a good UX by using monitoring software and by having plans for preventing and coping with outages.
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