Issue link: https://epubs.iltanet.org/i/4636
ILTA White Paper Infrastructure Technologies 18 need to be aware of before going with a VDI solution. Any flavor of VDI is going to cost more than Microsoft Terminal Services will. The reason VDI costs more, though, is because it will do more. However, if traditional Terminal Services works well for you, then stick with it, and don't look at VDI as an upgrade. Another thing to consider is whether you will be able to completely replace your legacy systems and use VDI for everyone. If the answer is no, then you could be left managing multiple systems for antivirus, patching and logon scripts. With advancements in application streaming, you should be able to run just about any application in a VDI environment, but you still need to consider the needs of your road warriors and other remote users. Offline VDI desktops are now available, but they are still first generation and a bit cumbersome to work with. While that probably won't be an issue in the future, it should be a big consideration now. Deciding to go with VDI also means that you might have to rethink your network topography, bandwidth requirements and Active Directory structure. Moving 500 user desktops from five different offices into the data center is going to require you to think closely about where your domain controllers are located, what backup capacity you have and what kind of resources (space and disk I/O) will be consumed on your SAN. These decisions will be heavily influenced by which VDI vendor you choose because some vendors stream the entire desktop, which will consume more bandwidth, while others advocate that you only stream applications but not the operating system (OS) itself. Storage concerns are also one of the key items that you have to consider very carefully. Almost all of the VDI vendors offer some sort of thin provisioning or dedupe technology that allows you to use as little storage as possible. This is a core feature of VDI because without it, not many of us would decide to go with VDI. If you assume a standard desktop image is 25GB (a reasonable estimate for the OS plus applications,) then 500 VDI desktops would consume over 12.5TB of storage on a SAN. With thin provisioning, your base image is 25GB while every other image comprises only user-specific settings and files, so each additional desktop amounts to just a small delta change. Even so, you'll still need to ensure that your SAN has enough spindles and storage to properly support a VDI deployment. Because VDI is still in its early years, the complexity of the unknown is definitely something you also need to consider. For the past eight or nine years, you could reasonably follow and predict what both Microsoft and Citrix would do, and their core products, TS and Presentation Server, simply did not "With advancements in application streaming, you should be able to run just about any application in a VDI environment, but you still need to consider the needs of your road warriors and other remote users."