March 24, 2011 at 4:08 PM

Which way to the cloud is about as contentious an IT topic as any, with industry experts and enterprise IT professionals staking out positions on either side of the private-public divide.

 In this week’s IT Counterpoint debate, two cloud experts with opposing ideas on how best to get started went head to head. Virtual private cloud (VPC) is the way to go, said one. Private cloud is best, said the other.

 “The virtual private cloud model allows the right balance between using this efficient technology with the security and control aspects an enterprise requires. This will allow them to experiment, learn fast and figure out how to make the cloud work,” said Sundar Raghavan, chief product and marketing officer with Skytap, which provides cloud automation solutions.

 By VPC, also known as hybrid cloud, Raghavan means use of a private cloud on top of public cloud infrastructure. “Virtual private cloud allows companies to use ‘public’ cloud with their own security and network policies acting as a private cloud,” he described.

 But why bother? That’s what fellow debater Erik Sebesta, chief architect and technology officer with Cloud Technology Partners, a cloud consultant, wanted to know.

 VPC lets companies experiment with cloud technology and figure out what does and doesn’t work – that’s why, Raghavan said. “Rather than take a long time to build a perfect internal cloud, a quick and fast learning experimentation is facilitated by VPC or hybrid cloud model.”

 “Why is VPC needed to experiment?” Sebesta countered.

 "Our CIO clients want to move to production fast to gain the cost advantages of private clouds, similar to what Amazon and Google get internally AND also get security and control,” Sebesta said.

 Yes, he added, private clouds are hard to build correctly, which makes following a “right” model an imperative.

 The right model, he described, includes simple, horizontally scalable services and inexpensive, reliable commodity hardware; assumes component failure; is fault-tolerant; scales by adding more CPU; maximizes use of open source software for less lock-in; automates management and self-service provisioning; enables a server administrator-to-machine ratio of 1 to between 1,000 and 3,000 servers; flexes with usage; and combines development and operation into a single discipline.

 Additionally, enterprises can experiment in the public cloud proper and not bother with a VPC, Sebesta argued. Or they can work on their private clouds in a “controlled manner with plenty of experimentation, learning as they go by doing it themselves.”

 The VPC-private choice may come down to company size, the debaters agreed.

 While larger enterprises can build their own clouds, small and midsized businesses often wouldn’t have the “luxury of a lot of time and budget,” as Raghavan said.

 For more of the VPC vs. private cloud discussion, read the full “What’s the best way to get started with the cloud?” debate here.

Beth Schultz

Beth Schultz , contributing editor, has more than two decades of experience as an IT writer and editor. You can find her work at a number of leading IT publications, where she writes on a variety of topics including cloud computing, mobility, network/systems management and security. Find her Linkedin profile here or e-mail her here.