desktop as a service (DaaS)

Desktop as a service (DaaS) is a cloud computing offering in which a third party hosts the back end of a virtual desktop infrastructure (VDI) deployment.

With DaaS, desktop operating systems run inside virtual machines on servers in a cloud provider's data center. All the necessary support infrastructure, including storage and network resources, also lives in the cloud. As with on-premises VDI, a DaaS provider streams virtual desktops over a network to a customer's endpoint devices, where end users may access them through client software or a web browser.

How does desktop as a service work?

DaaS architecture is multi-tenant, and organizations purchase the service through a subscription model -- typically based on the number of virtual desktop instances used per month.

In the desktop-as-a-service delivery model, the cloud computing provider manages the back-end responsibilities of data storage, backup, security and upgrades. While the provider handles all the back-end infrastructure costs and maintenance, customers usually manage their own virtual desktop images, applications and security, unless those desktop management services are part of the subscription.

Typically, an end user's personal data is copied to and from their virtual desktop during logon and logoff, and access to the desktop is device-, location- and network-independent.

VDI vs. DaaS

Desktop as a service provides all the advantages of virtual desktop infrastructure, including remote worker support, improved security and ease of desktop management.

Further, DaaS aims to provide additional cost benefits. Deploying VDI in-house requires a significant upfront investment in compute, storage and network infrastructure. Those costs have decreased, however, thanks to the emergence of converged and hyper-converged infrastructure systems purpose-built for VDI.

With DaaS, on the other hand, organizations pay no upfront costs. They only pay for the virtual desktops they use each month. Over time, however, these subscription costs can add up and eventually be higher than the capital expenses of deploying on-premises VDI.

Additionally, some advanced virtual desktop management capabilities may not be available for certain DaaS deployments, depending on the provider.

Use cases for desktop as a service

There are a number of potential use cases for desktop as a service. One common use case is in organizations that are especially concerned with data security. When properly configured, DaaS can mitigate many of the security risks associated with physical devices, such as the risks posed by removable media.

Desktop as a service may also be a good fit for organizations that want to ensure business continuity in times of disaster. During the COVID-19 pandemic, for instance, most knowledge workers were forced to work from home, where they may or may not have had a PC.

Desktop as a service enables employees to access fully provisioned corporate desktop environments remotely, and from a device of their choosing. This means that users can continue doing their jobs unimpeded by the fact that they cannot go into the office. This is just one example of using desktop as a service for business continuity. Since the virtual desktops are hosted in the cloud and accessible from anywhere, they could conceivably allow users to continue working after almost any disaster, as long as power and internet connectivity are available.

Benefits and drawbacks of desktop as a service

The most significant advantage to DaaS and similar desktop virtualization technologies is that virtual desktops are accessible from anywhere. This means that organizations that subscribe to DaaS can provide remote employees a user experience that largely mimics that of users who are working on site.

Another potential benefit of DaaS is that cloud service providers generally make it easy to scale up virtual desktop deployments. Because the virtual desktops are hosted on cloud infrastructure, organizations do not have to worry about acquiring and deploying additional physical hardware that is required when scaling on-premises VDI.

Just as cloud providers make it easy to scale up, they also usually make it easy to scale down. For some organizations, this can potentially help to reduce license costs. For example, if an organization hires seasonal workers during certain times of the year, DaaS would allow it to easily provision cloud-based virtual desktops for the seasonal workers. Once the season is over, the organization can just as easily deprovision those virtual desktops, eliminating the costs associated with the virtual desktops.

Another benefit of desktop as a service is that it allows users to work from the device of their choosing. A user might choose to work from a PC, a Mac or a mobile device, as long as it has the necessary display resolution and remote desktop client software. The user's desktop environment is identical, regardless of the type of device that they are using.

Desktop as a service can reduce software license costs. This is especially true for users who work from multiple devices. In these cases, an organization can install an application onto a single virtual desktop, thereby consuming a single license, rather than installing the application onto each of the user's devices, which would require multiple licenses.

Desktop as a service can potentially increase operating system license costs, however. This tends to happen when users access virtual desktops from company-owned desktops or laptops. In such a situation, a user's physical device would typically require an operating system and the virtual desktop would require a second operating system license. However, most cloud service providers bundle the operating system license cost into the cost of the virtual desktop.

The single biggest disadvantage of DaaS is that because the virtual desktops are hosted in the cloud, they must be accessed over the internet. If an organization were to experience an internet outage, it could leave employees unable to access their desktops. Similarly, a user who is working from home over a slow internet connection may experience poor virtual desktop performance.

Major DaaS providers

There are numerous providers that offer desktop as a service. Two of the best-known DaaS vendors are Citrix Managed Desktops and VMware Horizon Cloud.

However, Amazon is beginning to establish itself as a major DaaS player with its Amazon Web Services (AWS) Workspaces, as is Microsoft with Windows Virtual Desktop.