If an enterprise data center has a highly virtualized environment, a web portal for business users to request and access virtual machines and a method for tracking how many of those resources are being used... that's not quite a private cloud.
If there is enough capacity to supply employees with almost any amount of compute resources they need, and scale that capacity up and down dynamically, but it requires IT workers to provision the systems, then sorry that's not a private cloud either.
The line between virtualization and a private cloud can be a fuzzy one, and according to a new report by Forrester Research, up to 70% of what IT administrators claim are private clouds are not. "It's a huge problem," says Forrester cloud expert James Staten. "It's cloud-washing."
Why's it such a big deal? Staten says if you call a highly virtualized environment a cloud, but it doesn't have one or more of the key characteristics of a private cloud, then the IT department is setting an unrealistic expectation for users. If users are disappointed when they find out the environment doesn't have self-provisioning, or an elastic resources pool, they can get discouraged. The next time they need a VM on the fly, where will they turn? The pseudo-private cloud IT has set up, or Amazon Web Services, which IT could have no control over.
Most cloud experts have settled on a generally-agreed upon definition of cloud computing - be it public or private - as having the five characteristics outlined by the National Institutes for Standards in Technology. These include:
- On-demand, self-service for users
- Broad network access
- Shared resource pool
- Ability to elastically scale resources
- Having measured service
Without those five bullets, it's not technically a cloud. Contrary to some people's beliefs, virtualization is not a private cloud; it's an essential ingredient to powering clouds, but in and of itself it does not create one. Mike Adams, marketing manager for VMware, says a private cloud incorporates more sophisticated management capabilities on top of a virtualized environment, giving it the qualities outlined in the NIST definition.
Andi Mann, a vice president of Strategic Solutions at CA Technologies and cloud pundit, pumps the brakes a little bit on this discussion though. "If you don't have all five (characteristics), then you're getting into semantics," he says. The real question, he says, is not whether the five check marks can be made to call something a cloud - it's whether IT is serving its users appropriately. "Sometimes 80% of cloud is good enough," he says. "What it's really all about is business service. Who cares what you call it; what you care about is that your customers, your business users have the resources they need."
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