Desktop virtualization is a hot topic. According to a new survey of IDC, 45% of respondents, CIOs, said that 2012 has witnessed a hot narrative of desktop virtualization. Despite mass strong interest in this technology and many people are also try to work on that, the deployments of virtual desktop infrastructure (VDI) have failed because of diverse problems in performance and user experience. So why is that happened?

AS companies gradually nudge themselves into VDI production level from its testing and pilot projects, they began to realize it is not good to make system performance a hindsight and it is obsolete to solve the concerned problems passively. During or after VDI deployment, many invisible problems will shock those VDI project managers because everything is going through too smoothly during the pilot. 

Too much focus on desktop leads to ignorance of back-end infrastructure

when an enterprise starts its desktop virtualization technology, it usually focuses on a user's desktop. That is natural choose as computer end system is determined to be, after all, shifted from physical side to virtual machine. If decided to deploy VDI, you should focus on the performance testing of physical desktops, simulating a real use and predicting virtualized user experience. And based on these results you will find which desktops can be virtualized and which ones cannot.  This is also a way many people knew to assess VDI.

with VDI, one of the fundamental changes is that desktops no longer have proprietary resources; they share physical machine resources; and they may be used as a common storage subsystem. Although resource sharing brings benefits, it triggers problems. For instance, a single malfunctioned desktop might consume the sharing resources and lay a bad influence on other ones.

In the physical world, the impact of failure or performance degradation is almost insignificant，that is, if a desktop is out of order in real physical world, it will only affect one user. By contrast, the impact of failure or performance degradation happened in virtual world is much more serious because a broken down desktop may affect one hundred desktops. Therefore, even in VDI assessment, performance must to be involved to optimize the entire back-end infrastructure for virtual desktops. 

In fact, at each stage of the VDI life cycle, performance needs to be considered, because this is a basis for success or failure of VDI deployment. VDI existing new inter-desktop dependencies also need to be considered at every stage. For example, in many earlier deployment cases, administrators found that when they just shifted physical desktop to VDI, there would happen something defective in backup or anti-virus software. Such software components are arranged to run simultaneously on all desktops. And that is no problem if it is in the physical world because each desktop has its own dedicated hardware. But in VDI, resource requirement in synchronization of all desktops will stir up something seriously to the performance of virtual desktops. And it is unpredictable, because most design and planning work is coming out in a single desktop.