Like a football coach crafting game plans to best utilize his players, an IT professional thinking about a VDI installation must decide how to maximize the technology.
The decisions boil down to priorities. In the same way a coach may want to feature his star running back to power the offense, IT professionals may want to ensure that they have the right back-end infrastructure powering their VDI deployment.
When an organization decides to virtualize its desktops, IT must answer numerous critical questions that will affect both end users and the organization.
Desktop as a service or VDI?
One of the first decisions IT must make is where it will host its virtual desktops. There are two options: desktop as a service (DaaS) -- where IT outsources the back-end infrastructure to a service provider that hosts the desktops -- or VDI -- which requires IT to build the back-end infrastructure to host the virtual desktops in house. It is not a black and white choice, though. IT can combine DaaS and on-premises VDI if it so chooses.
In the short term, choosing mostly DaaS seems like the obvious choice -- it has a lower upfront cost than VDI because IT doesn't have to purchase and build the infrastructure itself. But, over the long term, DaaS subscription fees add up. And they don't go away, as IT never actually owns this portion of the infrastructure. Over several years, the total cost of subscription fees for DaaS can match and even surpass the large initial investment of deploying VDI.
The differences go deeper than just the cost; customization and performance are two other key factors. With DaaS, IT pros cannot fully control the infrastructure running their desktops because they do not have access to it. A VDI installation, however, puts all the pressure on IT to craft, manage and maintain the back-end infrastructure. It grants them far more control, but puts them on the hook for any potential errors.
Is HCI a good fit?
If IT forgoes DaaS, it should consider hyper-converged infrastructure (HCI) to power its VDI installation. HCI is a large investment, but it can ease the burden of VDI management by bringing the network, storage and compute hardware under one roof. Because everything is in one place with HCI, it should all work together seamlessly, which is not always the case when IT builds its infrastructure with pieces from different vendors.
Additionally, putting network, compute and storage hardware in one place enables more effective management. Lowering data storage constraints increases the number of virtual machines an organization can host on its VDI, as well.
Because HCI requires a minimum of three hypervisor hosts per appliance, it doesn't make sense to use HCI unless IT has several hundred virtual desktops. It is easy to scale up with HCI because IT can stack hypervisor hosts like building blocks.
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As a result, HCI is a great option for established organizations with plenty of resources to invest in the VDI installation. But small to medium-sized organizations should think carefully before investing in HCI because it may offer more capabilities than they need.
Persistent or nonpersistent desktops?
The choice between nonpersistent and persistent desktops comes down to what users need and the amount of resources IT is willing to devote to VDI.
A persistent desktop saves a user's changes each time he logs on. Like a physical desktop, settings, apps, wallpaper and color schemes are consistent every time he accesses his desktop. Every employee saving images and preferences eats up storage space quickly, however. As a result, IT must decide if it is willing to add more capacity into its VDI installation to allow users to maintain these settings.
If IT doesn't want to store the personalizations and app access, nonpersistent desktops are the best option. With nonpersistent deployments, the desktops reset each time a user logs out. As a result, these desktops take up very little storage space. The drawback, of course, is that users cannot save any settings or app access.
User needs often dictate IT's choice between persistent and nonpersistent desktops. If the company has a lot of task workers -- warehouse workers, data entry employees and retail employees -- it can get away with running nonpersistent desktops. Power users -- engineers and developers -- and knowledge workers -- finance and IT administrators -- require access to specific apps. This makes persistent desktops a better fit.