If an enterprise data centre has a highly virtualised 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 virtualisation 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."
In Forrester's reading, a private cloud is an extrapolation of server virtualization by providing self-service mechanisms where network/systems administrators can deploy services. From this perspective, a service is a business application comprised of components like Apache, MySQL, virtual machines with operating systems, application components (Java, database, and web content), and additional edge network configurations like load balancer and perhaps network-attached storage. However, a human being from the unit that manages IT still must deploy the virtual infrastructure that needed to meet a business need.