When it comes to virtual desktop infrastructure, administrators have a lot of choices. You may have wondered about the differences between VDI software options, remote display protocols or all the licenses out there. In this series, we tackle some of the biggest head-scratchers facing VDI admins to help you get things straight.
As cloud computing matures, more organizations are turning to the cloud to host their desktops. But what exactly is Windows as a Service, and what's the difference between VDI and Desktop as a Service?
With in-house VDI, virtual desktops are hosted in the company's data center, and the organization is responsible for all desktop management. Desktop as a Service (DaaS), on the other hand, means that a cloud service provider hosts desktops off-site and handles infrastructure costs and maintenance.
"Windows as a Service" is a term Citrix Systems Inc. uses to describe the running of virtual desktops on a cloud-based operating system, either on-premises (with a private cloud) or through a public cloud provider. This approach can be used to deliver Windows apps or full Windows desktops.
How Windows as a Service differs from VDI
Citrix customers now can deliver Windows as a Service from Azure using XenDesktop 7. With the licensing support for Remote Desktop Services (RDS) on Windows Azure, IT pros can run session desktops on Microsoft's cloud platform. XenDesktop 7 shops also can deploy Windows as a Service from other cloud provider platforms, such as Amazon Web Services.
In both cases, that means running XenDesktop management in Azure and hosting the workloads in the cloud, rather than on-premises. Since the XenDesktop 7 management infrastructure can handle RDS on Windows Server workloads, this is still within the licensing policies laid out by Microsoft, said Calvin Hsu, a Citrix spokesperson. (Running a client OS as a guest is not allowed.) "As long as all the workloads are Windows Server, and now Windows Client, everything is in the clear," Hsu said.
Running XenDesktop cloud-hosted session desktops is a good way to support mobility, because any type of app can be delivered to any type of device, over any type of network. But aren't those the benefits of disconnected VDI as well? Yes. The difference is the host platform.
With VDI, the guest OS is Windows Server (or some other on-premises server operating system).
With Windows as a Service, Citrix XenDesktop is based on Azure or some other cloud service, and apps and desktops are delivered from shared server-based sessions (à la RDS or XenApp). This allows IT to deliver individual apps or full desktops from shared server sessions.
Windows as a Service vs. DaaS
"Windows as a Service" sounds a lot like "Desktop as a Service." It means the same thing, and then some.
Windows as a Service describes everything from IT shops acting like an internal service provider in an enterprise by running XenDesktop 7 on a private cloud or a public cloud to hosting providers charging for a desktop service, which is what DaaS is. Windows as a Service also means the ability to deliver both Windows apps and full desktops, Hsu said.
The XenDesktop 7 on a public cloud scenario applies both to enterprises that want to start using public clouds like Azure for these workloads, and to service providers that want to use Azure as their back-end infrastructure as they deliver services to end customers, Hsu said.
Ultimately, running XenDesktop 7 on a public cloud platform eliminates the infrastructure complexities that come with setting up a VDI environment on-premises.
The cloud also allows IT to manage costs, extend capacity on demand, reduce lead time for procuring and configuring hardware, and reduce hardware sizing risk as loads fluctuate, according to Citrix.