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ANAHEIM, Calif. -- Desktop as a Service can deliver virtual desktops without the infrastructure complexities of VDI, but IT shouldn't jump to the cloud to save money or eliminate all desktop management burdens.
In fact, the end result of a Desktop as a Service (DaaS) project may look much different than the cure-all described in marketing brochures. DaaS may not even live in a public cloud.
In 2012, Hartford, Conn.-based health insurance provider Aetna Inc. moved toward DaaS in its search for a platform that is more resilient, expandable and cost effective than virtual desktop infrastructure (VDI). At the time, the company had a 40,000 seat XenApp/XenDesktop platform.The must-have boxes Aetna needed to check off for DaaS included lower costs, fast deployment, disaster recovery, support for growth bursts, and seamless integration. That was a tall order two years ago, said Paul Stansel, senior engineering advisor for Aetna, who presented a session here at Citrix Synergy this week on his experience with a DaaS initiative.
Hard DaaS lessons learned
One of the first lessons Stansel learned is that DaaS is not necessarily cheaper than VDI; cost savings depend on existing costs. But companies will change their cost model to a fixed cost instead of a nebulous one, he said.
"No one can tell you with a straight face that DaaS will be a cheaper solution for you," without seeing your environment, Stansel said. "We were able to get a lower cost model."
And don't expect DaaS to increase security; it is only as secure as the rest of your environment, he said.
"If you think DaaS will solve your security problems, you probably have a pretty big security problem to begin with," Stansel said.
We went out guns blazing with DaaS, but had to reel it in.
Paul Stansel, senior engineering advisor for Aetna
Aetna needed cloud desktops that worked seamlessly with its existing Citrix infrastructure. At the time, VMware and Amazon didn't offer cloud desktops, but Citrix partners did. Still, there weren’t a lot of DaaS providers that could support the 15,000 desktops the company required, and latency was a problem, so Aetna wanted its workstations near their cloud provider's datacenters.
Microsoft licensing was a problem, too, because the Service Provider Licensing Agreement prohibits Windows client multi-tenancy. DaaS providers offer Remote Desktop Services as the cheapest and most common option, and users may not even know their desktops are on a Windows Server 2008.
Other options include a Windows Server OS skinned to look like a Windows desktop, which Amazon Workspaces and many DaaS providers offer today. Another approach is a VDI setup in a DaaS implementation where customers bring their own Windows license, but that increases the cost.
"We could do DaaS cheaper in-house than most providers," Stansel said.
And it does. Aetna worked with multiple vendors and by 2013, came up with its own DaaS service on-site in a caged-off area of its data center, using third-party equipment and its own Windows licenses.
"We relied on [vendors] to provide services, while they used some of our software and services," Stansel said.
Defining roles and who owned what became very important to maintaining Aetna's DaaS cost model, and took time to iron out. Knowing the inner workings of the DaaS build helped.
"I'm not going to lie and say it went smooth as silk," he said. "When something goes wrong -- and it will -- you need to understand the base technologies."
Now, the company delivers cloud desktops to 15,000 users alongside 23,000 VDI desktops, all in-house.
"We went out guns blazing with DaaS, but had to reel it in," he said.
IT shops eyeing DaaS should know what they are getting up front and what the service-level agreement (SLA) is.
Outages can occur at any time, and IT pros should know from their SLA how much downtime the cloud provider allows for. Amazon WorkSpaces experienced increased error rates for new WorkSpace launches and for existing Amazon WorkSpace connections in the US-EAST-1 Region for more than two hours on April 30, for instance.
The data center’s location is also important, because geography matters for cloud desktop performance. There aren't DaaS providers with services everywhere global users reside, so this could be a problem.
IT shops must understand how flexible the desktops will be, and bring in an outside consultant to audit the service provider's DaaS design, Stansel said.