Using virtualization, some companies are building private cloud computing environments intended to be used only by their employees or designated part-ners. Also referred to as internal clouds, private clouds can offer the benefits of public cloud computing, while still enabling the organization to retain greater control over the data and process.
NIST describes a private cloud as a cloud infrastructure operated solely for an organization, managed by the organization or a third party and existing either on premise or off-premise. The private cloud is typically hosted within the boundaries of the owner organization.
While the concept of a private cloud may create some cognitive dissonance (isn’t the purpose of cloud infrastructure to be shared?), there are some specific characteristics of a private cloud that differentiate it from the traditional IT distributed infrastructure.
Firstly, private clouds differ from public clouds in that the infrastructure associated with a private cloud is commonly dedicated to a single enterprise and is not shared with any other enterprise. This infrastructure may include many corporate offices, business partners, intranet clients/vendors, resellers, or any other groups engaged in a business relationship with the enterprise.
Secondly, security is considered to be tighter in a private cloud deployment than it is in a public cloud. Obviously, a private cloud is not inherently more secure than a public cloud unless secure best practices are being followed, but an enterprise that has security, risk, or compliance concerns may want to exert the control a private cloud can offer, as the enterprise owns the infrastructure and has control over how applications are deployed on it.
Also, a private/hybrid cloud may help an enterprise prepare for the future, by leveraging existing infrastructure into a cloud. As the IT department begins to implement virtualization products into future data center plans, a private
Private cloud deployment appears to be spearheaded primarily by larger organizations and governmental agencies, rather than small companies or end users. The difference in startup costs is a major reason for this. A private cloud requires much of the same infrastructure outlay that traditional IT infra-structure requires, so an institution would need to be fairly large to get ben-efits from the private cloud model.