What is VDI (virtual desktop infrastructure)?

Virtual desktop infrastructure (VDI) is defined as the hosting of desktop environments on a central server. It is a form of desktop virtualization, as the specific desktop images run within virtual machines (VMs) and are delivered to end clients over a network. Those endpoints may be PCs or other devices, like tablets or thin client terminals.

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How does VDI work?

In all VDI deployments, the following characteristics apply:

  • The virtual desktops live within VMs on a centralized server
  • Each virtual desktop includes an operating system image, typically Microsoft Windows
  • The VMs are host-based, meaning multiple instances of them can housed on the same server within the data center
  • End clients must be constantly connected to the centrally managed server in order to maintain access to the virtualized desktops it’s hosting
  • The VDI implementation’s connection broker finds a virtual desktop within the resource pool for each client to connect to upon its successful access of the VDI environment
  • Meanwhile, a hypervisor creates, runs and manages the various host machine VMs that encapsulate the individual virtual desktop environments

In modern digital workspaces in which numerous apps must be accessed on demand, VDI facilitates secure and convenient remote access that helps boost employee productivity. Furthermore, it enables a consistent experience across multiple devices.

VDI vs. desktop virtualization

Not all types of desktop virtualization leverage host-based VMs like VDI does. Also, VDI is not synonymous with desktop virtualization as a category. Instead, it is an alternative to other forms of virtual desktop delivery, including hosted shared solutions that connect PCs and thin clients to a shared desktop, as well as local desktop virtualization, in which the desktop environment runs directly on the client.

VDI in digital workspaces

Assuming all supporting infrastructure is functioning as intended, a user who remotely accesses a VDI solution from their endpoint can manage the OS and the applications and data on it as if they were running locally. This setup lets workers safely access everything they need from virtually any device, without requiring specific hardware.

Augmented by solutions for convenient single sign-on (SSO) and secure remote access, virtual desktops can also be run and managed alongside the growing spectrum of cloud, web and mobile apps integral to modern workflows. Employees get a unified experience that enables greater productivity, while IT avoids silos and mitigates the risk of unauthorized logins.

In other words, VDI in the context of a digital workspace platform contributes to a superior working environment without compromising on security. However, the exact ways in which VDI will benefit users and IT will depend on the particular deployment type.

Persistent vs. nonpersistent VDI deployments

Under persistent VDI, a user always logs into the same desktop image, with all changes to its applications and data retained. That allows for full personalization. In contrast, nonpersistent VDI doesn’t save any changes.

Persistent VDI works as follows:

  • A user is assigned a standardized desktop from the resource pool the first time they log on
  • Each subsequent time they access the VDI environment, they are connected to the same desktop, with all of their changes retained in the virtual OS image even after the connection is restarted
  • For workers with complex and fast-paced digital workflows, this means they can easily pick up where they left off and benefit from extensive personalization of the desktop’s virtual apps and settings

In contrast, nonpersistent VDI works as follows:

  • The end client may be connected to the same desktop every time or to a randomized one from the pool
  • In either case, no changes are saved upon restarting
  • A nonpersistent VDI implementation is well-suited to one-off access to a desktop but not to using a virtual desktop exactly like a personal physical equivalent, which requires persistent VDI

Since nothing is saved once the connection is terminated, IT does not have to maintain a large number of customized OS images, allowing for simplified data center management and reduced costs. Nonpersistent VDI also streamlines the management of devices for kiosk and task workers who don’t need to save anything.

What are the benefits and limitations of VDI?

VDI supports enhanced user mobility and remote access, as a standardized desktop can be reached from almost any approved and compatible endpoint in any location. For workers who are frequently on the go and need to pull up a virtual desktop containing a full range of virtual apps and data, VDI is like having an office available on-demand. In that regard, it fits right into their digital workspace workflows that already feature similar, regular consumption of cloud, web and mobile apps across multiple contexts, especially if it’s persistent VDI.

Cost savings and lower hardware requirements

Beyond benefits for end users, VDI technology can also be a strong cost-saving measure for IT:

  • Because the lion’s share of processing in VDI is server-based, relatively expensive or cutting-edge hardware is not needed
  • VDI access can instead take place from an inexpensive thin client, which might be an old PC that has been repurposed for the task and thereby had its lifespan extended
  • That saves IT the need to make as many new purchases or major adjustments to its budget

Improved security and centralization

On the security front, VDI offers some improvement over running an OS and everything on it locally. All of the data from a VDI connection lives on the server, not the end client, meaning that if the endpoint is ever stolen, there’s nothing to exfiltrate from its local storage.

Moreover, the VDI environment is fully and centrally controlled from a data center. Administrators can apply software patches and updates, change configurations and enforce policies for all virtual desktops across the deployment. In this way, VDI allows for fine-tuned control and secure isolation of OS images from a central server, which is a less complicated setup that managing laptops running their OSes locally.

Security and performance considerations

At the same time, security cannot be taken for granted with VDI. The OS images have to be properly managed and updated, and end client authentication must be rigorous. Digital workspace solutions can help in this regard via SSO, improved endpoint security and encryption for data in transit.

Performance is another key consideration with VDI:

  • When it first became widely available in the mid 2000s, VDI’s typical performance lagged visibly behind that of a local OS
  • Over time, this gap has closed significantly, but users might still feel they’re not always getting the best possible experience
  • Occasional performance-tuning and reviews of the VDI deployment are advisable to make sure that solvable technical problems are addressed

What are the use cases for VDI?

VDI is an important technology for many types of workers across numerous industries. Remote and mobile employees, contractors, kiosk and task workers, field technicians, medical professionals, teachers and many others regularly rely on VDI to access a reliable virtual desktop from one or more locations. Thanks to the versatility of VDI across its different deployment types, VDI technology can work equally well as a way for users to have access to standard, nonpersistent desktop or to turn their virtual desktop into a highly personalized digital workspace.

How does VDI support digital workspaces?

Digital workspaces are application-driven. Within them, secure and straightforward access to multiple types of applications, including those virtualized via a VDI OS image, is essential.

A reliable, economical VDI solution helps scale key applications and services to today’s increasingly mobile and remote teams. VDI delivers a consistent experience across devices including PCs, tablets, smartphones and thin clients, giving employees and contractors a high degree of freedom in how they work. It allows for more streamlined and unified workflows.

VDI can improve cybersecurity and reduce IT overhead as well. With data breaches becoming more costly with each passing year, VDI’s isolation and centralization can be a pivotal component in a multilayered security strategy. It also spares IT the complications of having sensitive data stored locally on client devices.

How does Citrix help with VDI?

Citrix offers a diverse portfolio of desktop virtualization solutions serving organizations of all sizes and kinds. Citrix Virtual Apps and Desktops makes VDI intuitive and affordable and ensures that users have access to the apps they need to remain productive within today’s digital workspaces. Alongside Citrix Workspace, it can ensure the best possible VDI experience within the context of complex multi-device, multi-app workflows. Citrix Workspace gives employees comprehensive and secure access to everything they need to stay productive from anywhere.

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