Ongoing hype around private cloud computing is creating misperceptions about private cloud, according to Gartner, Inc. To help reduce the hype and identify the real value of private cloud computing for IT leaders, Gartner explains five common misconceptions about private cloud.

"The growth of private cloud computing is being driven by the rapid penetration of virtualization and virtualization management, the growth of cloud computing offerings and pressure to deliver IT faster and cheaper," said Tom Bittman, vice president and distinguished analyst at Gartner. "However, in the rush to respond to these pressures, IT organizations need to be careful to avoid the hype, and, instead, should focus on a private cloud computing effort that makes the most business sense."

The five misconceptions about private cloud and the corresponding realities are:

1. Private Cloud Is Not Virtualization

Server and infrastructure virtualization are important foundations for private cloud computing. However, virtualization and virtualization management are not, by themselves, private cloud computing. Virtualization makes it easier to dynamically and granularly pool and reallocate infrastructure resources (servers, desktop, storage, networking, middleware, etc.). However, virtualization can be enabled in many ways, including virtual machines, operating systems (OSs) or middleware containers, robust OSs, storage abstraction software, grid computing software, and horizontal scaling and cluster tools.

Private cloud computing leverages some form of virtualization to create a cloud computing service. Private cloud computing is a form of cloud computing that is used by only one organization, or that ensures that an organization is completely isolated from others.

2. Private Cloud Is Not Just About Cost Reduction

An enterprise can reduce operational costs with a private cloud by eliminating common, rote tasks for standard offerings. A private cloud can reallocate resources more efficiently to meet enterprise requirements, possibly by reducing capital expenses for hardware.

However, private clouds require investment in automation software, and the savings alone might not justify the cost. As such, cost reduction is not the primary benefit of private cloud computing. The benefits of self-service, automation behind the self-service interface and metering tied to usage are primarily agility, speed to market, ability to scale to dynamic demand or to go after short windows of opportunity, and ability for a business unit to experiment.

3. Private Cloud Is Not Necessarily On-Premises

Private cloud computing is defined by privacy, not location, ownership or management responsibility. While the majority of private clouds will be on-premises (based on the evolution of existing virtualization investments), a growing percentage of private clouds will be outsourced and/or off-premises. Third-party private clouds will have a more flexible definition of "privacy." A third-party private cloud offering might share data center facilities with others, could share equipment over time (from a pool of available resources), and could share resources, but be isolated by a virtual private network (VPN) and everything in between.

4. Private Cloud Is Not Only Infrastructure as a Service (IaaS)

Server virtualization is a major trend and, therefore, a major enabler for private cloud computing. However, private cloud is not limited in any way to IaaS. For example, with development and test offerings, enabling higher-level Platform as a Service (PaaS) offerings for developers makes more sense than a simple virtual machine provisioning service.

Today, the fastest growing segment of cloud computing is IaaS. However, IaaS only provides the lowest-level data center resources in an easy-to-consume way, and doesn't fundamentally change how IT is done. Developers will use PaaS to create new applications designed to be cloud-aware, producing fundamentally new services that could be very differentiating, compared with old applications.

5. Private Cloud Is Not Always Going to Be Private

In many ways, Gartner analysts said that private cloud is a stopgap measure. Over time, public cloud services will mature, improving service levels, security and compliance management. New public cloud services targeting specific requirements will emerge. Some private clouds will be moved completely to the public cloud. However, the majority of private cloud services will evolve to enable hybrid cloud computing, expanding the effective capacity of a private cloud to leverage public cloud services and third-party resources.

"By starting with a private cloud, IT is positioning itself as the broker of all services for the enterprise, whether they are private, public, hybrid or traditional," Mr. Bittman said. "A private cloud that evolves to hybrid or even public could retain ownership of the self-service, and, therefore, the customer and the interface. This is a part of the vision for the future of IT that we call 'hybrid IT.'"

Additional information is available in the Gartner report: Five Things That Private Cloud Is Not