Private cloud is a type of cloud computing that delivers similar advantages to public cloud, including scalability and self-service, but through a proprietary architecture. Unlike public clouds, which deliver services to multiple organizations, a private cloud is dedicated to a single organization.
As a result, private cloud is best for businesses with dynamic or unpredictable computing needs that require direct control over their environments.
Public and private cloud deployment models differ. Public clouds, such as those fromAmazon Web Services or Google Compute Engine, share a computing infrastructure across different users, business units or businesses. However, these shared computing environments aren't suitable for all businesses, such as those with mission-critical workloads, security concerns, uptime requirements or management demands. Instead, these businesses can provision a portion of their existing data center as an on-premises -- or private -- cloud.
A private cloud provides the same basic benefits of public cloud. These include self-service and scalability; multi-tenancy; the ability to provision machines; changing computing resources on-demand; and creating multiple machines for complex computing jobs, such as big data. Chargeback tools track computing usage, and business units pay only for the resources they use.
In addition, private cloud offers hosted services to a limited number of people behind a firewall, so it minimizes the security concerns some organizations have around cloud. Private cloud also gives companies direct control over their data.
But private clouds have some disadvantages. For example, on-premises IT -- rather than a third-party cloud provider -- is responsible for managing the private cloud. As a result, private cloud deployments carry the same staffing, management, maintenance and capital expenses as traditional data center ownership. Additional private cloud expenses include virtualization, cloud software and cloud management tools.
However, to reduce an organization's on-premises IT footprint, cloud providers, such asRackspace and VMware, can deploy private cloud infrastructures.
A business can also use a mix of a private and public cloud services with hybrid clouddeployment. This allows users to scale computing requirements beyond the private cloud and into the public cloud -- a capability called cloud bursting.