VDI and Its Key Implementation Considerations

Virtual Desktop Infrastructure (VDI)

Virtual Desktop Infrastructure (VDI) is the practice of hosting a desktop operating system within a virtual machine (VM) running on a centralized server. VDI is a variation on the client/server computing model, sometimes referred to as server-based computing. 

In the past couple of years, some large organizations have turned to VDI as an alternative to the server-based computing model used by Citrix and Microsoft Terminal Services.

Virtual Desktop Infrastructure (VDI) is a desktop-centric service that hosts user desktop environments on remote servers and/or blade PCs, which are accessed over a network using a remote display protocol. A connection brokering service is used to connect users to their assigned desktop sessions. For users, this means they can access their desktop from any location, without being tied to a single client device. Since the resources are centralized, users moving between work locations can still access the same desktop environment with their applications and data.[3] For IT administrators, this means a more centralized, efficient client environment that is easier to maintain and able to respond more quickly to the changing needs of the user and business.

Key Implementation Considerations 

There are plenty of considerations regarding hosting Virtual Desktop Infrastructure (VDI) in the enterprise. Following are three of the most significant: 

Licensing :

Organizations underestimate the impact of Windows client licenses in a VDI environment. Microsoft licensing can be complex and VDI licensing can be even more complicated. Generally speaking, Microsoft charges for each device connecting to VDI, the license for the VDI instance and, if the endpoint runs Windows, it requires a traditional license as well. This is an area that needs to be well researched prior to undertaking a VDI implementation. 

Desktop Management :

Hardware costs are not the only consideration for VDI clients. Many organizations are tempted to use traditional desktops to access the VDI infrastructure, especially as the price difference between fully loaded desktops and thin clients continues to narrow. The cost and convenience should be weighed against the management cost. For every traditional desktop that is leveraged for VDI access, you essentially double your management overhead for each user. It's not just the VDI instances that must be maintained; physical clients still need software and security updates.

Storage :

Most virtualization engineers are aware that physical memory is the normal bottleneck for virtualized environments. Storage I/O is more of a concern for VDI environments. The use patterns of end-user workstations are very different from those of servers'. As a result, storage I/O can be the biggest performance headache for system optimization. To that end, hyper-converged platforms -- where the hypervisor itself is built in -- are quickly becoming the preferred strategy for VDI due to performance, cost and reliability.