When companies are considering moving to a VDI framework, they’ll have to think about whether to utilize stateful or stateless VDI designs. Companies can get massive efficiencies by moving machines to VDI. Sometimes this is done in conjunction with moving to a new operating system, or in the context of other legacy migration projects. However, in the process of planning, the company will have to figure out whether it’s best to incorporate a stateful or “persistent” model, or a stateless or “non-persistent” one.

Basically, in a stateful VDI model, user information gets saved between sessions, and users can customize desktops in ways that will still be there when they come back. Stateless VDI is different because engineers use ‘clones’ to spin up a VDI desktop environment for a given session. Information is not saved for a future session. The environment resets to a kind of “factory default” each time a session is over.

Young woman working at a desk with laptop and cup of coffee


The Value of Stateful VDI

In deciding which model to use, it’s important for companies to remember that stateful VDI is what people are used to. Prior to a VDI environment, desktops were local and hardware-based, and so they were stateful and customizable. All of the persistent data was right on the physical hard drive, and this fact really contributed to how software engineers built functionality.

Even newer cloud applications and web services are stateful. In cloud models, the persistent data is held at the vendor’s remote location. Most customers would not like to use a cloud service with a non-persistent design!

Even on the Internet, which was essentially built as a stateless environment, tools like cookies or other history caches provide stateful results such as remembering passwords, etc. One of the biggest kinds of pushback against the privacy violations that some associate with cookies and trackers has to do with the convenience of being “remembered” as you use a site. So although you can save money going with stateless VDI, you may end up with a system that users are frustrated with!

There is also the reality that it’s harder to manage customized user applications in a stateless VDI environment. Apps that need to be logged into for each session, or those with web forms or other sophisticated controls, will often use stateful design pretty profoundly. So when that is missing, it gets noticed. People may complain that a stateless VDI is like a “shell” where all of the imaging is there, but none of the long-term use is supported in ways that we have come to expect.

The Value of Stateless VDI

On the other hand, stateless VDI is often cheaper and easier to maintain. For many companies, though, the best benefit of stateless VDI is in cybersecurity. Many of the types of cybersecurity threats that can bring down enterprise operations or lead to data breaches are tied to a stateful design.

To succeed, the hacker needs to introduce some kind of threat to a stateful system where it will persist and do its damage. That’s worlds more difficult if the whole interface is cleared or wiped after a user session. Experts would say that stateless VDI presents a very thin attack surface to black hat actors. Where data security is paramount, stateless design can be much better for privacy. Medical HIPAA protocols are a prime example.

In addition, stateful VDIs work well in Evergreen IT / Windows-as-a-Service environments as you generally treat the OS migration on a stateful VDIs like you treat a physical OS migration. The only difference is that for stateless VDIs, you simply build a new machine. This way, you can introduce a new OS every time you upgrade which makes the whole upgrade process much easier. 

Another advantage to stateless is storage management as there are many cost-effective ways to manage storage, for example splitting users, application personalization, and VDI data storage. There are a lot of efficiencies that can be made use of in this area since not all machines are using all storage at one time but only when they are in use. This way, you have options when it comes to storage solutions and speed.

Stateless and Stateful VDI and End-User Analysis

One way to determine whether to use a stateful or stateless VDI design is to talk about something like T-shirt sizing, which is a relative estimation technique that can show some of the metrics that determine what approach should be used. For example, company leaders can brainstorm, looking at key stakeholders and dependencies, to figure out from identity and access profiles whether stateful VDI is necessary or not.

They may look at how many hours a given user spends on a VDI system, or what their role is within the company. Again, if this is someone who is responsible for long-term planning, they’re probably going to need a stateful VDI environment. If, however, they are a service level end-user who just uses the VDI to achieve one customer transaction at a time, stateless VDI may be fine.

Times to Use T-shirt Sizing in VDI Planning

One of the best times to use this kind of planning is at kickoff. Here, decision-makers will be looking at this from an initiative context and will be able to plan accordingly. Another opportunity is during project management when you’re looking at how VDI is actively being used and how it can be optimized. Look to this kind of planning for key decisions in IT automation, app packaging, and more. Access IT Automation can help you evaluate your estate using precise data collected from Access Symphony so you can base your decisions on facts, not gut-feel.