Organizations are moving to the cloud-hosted desktop model for many reasons, including cost, flexibility and disaster recovery. Make sure you understand how DaaS differs from in-house VDI as you consider this setup.
The majority of DaaS systems today focus on Windows-based virtual desktops, with a few serving Linux-based virtual desktops. While DaaS is generally thought of as an off-site virtual desktop solution, it isn't required to be off site. The DaaS provider may be responsible for designing and managing automated support for virtual desktops, but the location of the infrastructure can be on the company premises.
Companies interested in DaaS can compare the service offerings, expertise and consumption model of delivering virtual desktops in-house with the efficiencies of outsourcing to a DaaS provider.
Why deploy DaaS?
IaaS. Businesses are taking advantage of Infrastructure as a Service (IaaS) and moving applications and data to service providers. After such a move, these businesses may find that performance and the user experience degrade as the data and server applications move further away from the clients and users accessing them. To improve performance in such cases, IaaS providers may offer a virtual desktop from the same data center where the business apps and data are located.
Cost of supporting desktops. The high operational cost of deploying and maintaining Windows desktops is causing businesses to consider outsourcing to specialized service providers. DaaS allows customers to gain all the benefits of virtual desktops without having to acquire the in-house knowledge and skills necessary to deploy applications.
Seasonal workers. A company whose employee base grows and shrinks throughout the year may invest capital and human resources to build a desktop infrastructure for peak resource requirements. This means that businesses are not receiving full value from their capital IT investments, because some capacity is underused when the employee count shrinks.
DaaS products enable virtual desktop environments to grow and contract with organizational needs. DaaS pricing is typically based on a monthly cost and allows businesses to pay for virtual desktops and the supporting infrastructure only when they are needed.
Disaster recovery and business continuity. Virtual desktops are often looked at as an alternative to secondary sites full of PCs for disaster recovery or business continuity planning. When rapid provisioning and scalability are needed, DaaS is a perfect fit. Using DaaS disaster recovery and business continuity can also alleviate the capital and human costs of provisioning hardware that will be used only in an emergency.
How does DaaS compare with in-house VDI?
DaaS providers are keenly interested in offerings that have well-defined incremental growth costs. Grid solutions such Citrix VDI-in-a-Box isolate compute and storage into a "brick," a single piece of hardware. They allow for smaller units of growth than large enterprise storage arrays, which are underprovisioned until the moment they're overprovisioned and require large amounts of capital up front.
These so-called grid solutions also help DaaS avoid violating the Microsoft Product Use Rights that prohibit multiple customers from sharing hardware resources. A single brick, or set of bricks, can isolate the compute and storage for a single company from another brick that supports other virtual desktops.
In-house VDI typically favors enterprise shared storage, shared blade server components and conformity with the rest of the IT infrastructure versus the compute and storage isolation in DaaS. In-house VDI components may add costs and dependencies when compared with a DaaS model.
More on DaaS
FAQ on Desktop as a Service
Five challenges of DaaS
Pros and cons of hosted virtual desktops
DaaS providers may offer a Windows Server product such as Remote Desktop Session Host to achieve better multi-tenancy and lower the cost of delivering a virtual desktop. DaaS systems may also broker a Windows Server OS on a 1:1 basis to achieve the OS isolation of VDI while avoiding the expensive and complex Windows VDA and Companion Device licensing.
In-house VDI users may prefer a Windows desktop OS because they do not have the same Microsoft multi-tenancy end-user license agreement (EULA) challenges as a DaaS provider trying to achieve the highest return for its infrastructure investment.
Endpoints are largely unaffected by the choice between in-house VDI and DaaS. They are most affected by bandwidth and the latency of the virtual desktops they access. IT management of endpoints, whether via in-house VDI or DaaS, will be similar unless specific services are requested of the DaaS provider. DaaS solutions do not typically have special requirements or features for endpoint management or user experience.
Security differences between in-house VDI and DaaS are most likely the result of expertise, architecture and design rather than specific technology choices. Customers and DaaS providers ultimately rely on the same commercially available technologies to secure virtual desktops.
However, DaaS providers that focus on vertical markets sensitive to security, such as the federal government, typically have better processes, audit trails, focus on security technologies, and segmentation of logical and physical components than VDI designed in-house.
This was first published in July 2013