Understanding Citrix VDI

Application virtualization and desktop virtualization can take different forms. To figure out which one is right for your organization, it’s not always enough to know how they differ in a general sense. It’s also helpful to understand how different solution providers approach them.

Citrix is a company that’s become closely aligned with virtualization technology over the past two decades. Products like Citrix Workspace and Citrix Virtual Apps and Desktops (formerly Citrix XenApp and Citrix XenDesktop) are often top of mind when IT staff are looking for ways to equip end users with flexible digital workspaces and productivity apps. Now that remote and hybrid workplaces are the norm, that need is greater than ever.

Below we’re going to examine one form of desktop virtualization—specifically, virtual desktop infrastructure (VDI)—and what it looks like in a typical Citrix environment. We’ll cover the user experience, the provisioning process and some performance-impacting factors like bandwidth, latency and VPNs. And we’ll close by considering whether the Citrix desktop is even necessary for all use cases, or if alternative virtualization solutions are better suited to some workloads than others.

How does VDI work?

Virtual desktop infrastructure involves desktop environments hosted on a centralized server. This server, often located in an on-premises data center, stores and runs virtual machines that themselves hold micro-environments based on operating systems like Microsoft Windows. When they’re accessed by endpoint devices via the VDI software, these virtual machines help create an experience that’s similar to using a conventional desktop PC.

If we break that concept down into its individual components, it looks something like this:

    • A centralized server hosts virtual machines (VMs). Provided the hardware resources (e.g., CPU, RAM) are up to the task, it’s possible to have multiple virtual machines running on a single host server.
    • The software that generates, runs and manages the VMs is called a hypervisor.
    • Each VM contains one or more virtual desktops based on an operating system (OS) image—essentially a software snapshot of a PC. Although that OS image is usually some version of Windows, it can be a Linux variant too.
  • Endpoint devices connect to the server in an attempt to acquire a virtual desktop. Sometimes these endpoints are standalone PCs. More commonly, they are thin clients and zero clients, which are partially or completely dependent on desktop virtualization.
  • An additional software layer known as a connection broker identifies a virtual desktop for each of these endpoint devices and pairs the client device with the server-based operating system image.
  • Because the desktop environment originates on the host server in the data center, endpoint clients have to remain connected to it for the duration of the computing session.

In other words, there are a lot of moving parts to any VDI implementation. Having to itemize all these components just to make sense of VDI technology highlights its inherent complexity.

What is Citrix VDI?

As noted above, VDI is a form of virtualization technology. Citrix VDI is simply one company’s implementation of that technology. 

Citrix VDI therefore follows the same broad template—hypervisor, connection broker, endpoint devices—as other VDI solutions such as VMware Horizon. And, like many other virtualization solutions, Citrix leverages Microsoft’s Remote Desktop Protocol (RDP) to provide users with access to Windows apps and desktops.

However, with a view to optimization, Citrix introduces a stack of proprietary components that are ostensibly designed to improve aspects like access and management. These include:

  • Citrix Receiver: User-facing software for endpoints to connect to remote desktop resources.
  • Citrix ADC: Formerly known as Citrix NetScaler. Helps with load balancing and performance enhancements. 
  • Citrix StoreFront: Allows for end-user authentication and management of user information.
  • Citrix Director: Enables support-oriented IT staff or help desk teams to troubleshoot issues.
  • Citrix HDX: A suite of technologies for creating a near-native “high-def” user experience.
  • Provisioning Services (PVS): Designed for provisioning remote desktops from a shared master image.

Some of these components are Citrix-specific names for standard VDI technology. Others exist on top of the basic virtual desktop infrastructure, adding even more moving parts to the already complex VDI paradigm.

What are the limitations of VDI?

VDI—whether Citrix or not—is based on legacy desktop virtualization technology and comes with a number of caveats. You can boil these down to three major categories.

Cost: VDI requires a significant investment in both hardware and software before it can be up and running. Even if an organization has an established on-premises data center, any VDI solution will require multiple dedicated servers to function as hypervisor hosts and connection brokers. End users will also need to be equipped with a fleet of compatible endpoint devices.

Security: Microsoft RDP is a common target for brute force attacks and can quickly become a serious ransomware liability if proper precautions aren’t taken. Virtual private networks (VPNs) are often used in conjunction with VDI to give off-network users access to the internal network. Unfortunately, if an authorized end-user’s machine is compromised, VPNs can give hackers access to the internal network too.

Performance: Because VDI attempts to replicate a traditional local desktop on remote endpoints, the overall experience is subject to bandwidth constraints, high latency and other common connectivity issues. IT staff routinely end up fine-tuning the VDI solution to account for ongoing changes in the computing environment. When you factor in provisioning, image maintenance and other management responsibilities, virtual desktop infrastructure can eat up even more resources, leading to snowballing costs.

A more general limitation is that VDI predates the cloud, so it wasn’t designed to natively leverage platforms like Azure. Desktop-as-a-service (DaaS) has been one way that solution providers have tried to translate classic desktop virtualization to the cloud infrastructure, but that comes with its own set of potential complications.

Citrix VDI after the acquisition

One further consideration that relates specifically to Citrix VDI is the company’s future direction. In January, Vista Equity Partners and Evergreen Coast Capital announced that they had acquired Citrix Systems with a mid-2022 finalization.

Industry analysts expressed some wariness toward that news. According to a statement released by IBRS:

“Organisations re-evaluating their VDI investments — especially in light of Citrix’s request acquisition, should consider the potential of application virtualisation, and perform a detailed RIO that includes not just the licensing and hardware, but also the operational costs over an extended period — say five years. 

It should also be noted that, with Citrix being acquired, many organisations have started to be less optimistic about new innovation coming from the platform.”

What makes that potential lack of innovation especially concerning is that VDI solutions are known for their vendor lock-in. After organizations have sunk so much time and money into all the components of their virtual desktop infrastructure, they’re in no rush to migrate away from it. But that could leave them at the mercy of a stagnating desktop virtualization solution.

Solve for VDI’s limitations with Cameyo

Cameyo addresses the limitations of VDI altogether, thanks to its versatile, cost-effective and secure Virtual App Delivery (VAD) platform. VAD enables users to access essential apps and data quickly and easily from any device.

With Cameyo, organizations of any size can easily equip their end users with right-sized cloud desktops — wherever those users happen to be. Cameyo’s pioneering approach to Virtual App Delivery eliminates time-consuming provisioning processes. It doesn’t require VPNs. It’s cloud-native. And it’s far more intuitive to administer and use.

Getting started with VAD is as seamless as its user experience. Take advantage of your free trial or schedule a demo today to see how Cameyo can free you from the constraints, cost and complexity of VDI.