It can be confusing to keep track of the differences between all of the various types of clouds: Public Cloud, Private Cloud, Hybrid Cloud and Community Cloud. Which one is right for you and your company? In this article, we’ll look at private clouds and their benefits.

A private cloud delivers business functions as services. Private clouds are accessible and usable only by specific individuals within an organization and the private environments they create are supported by virtualized computing resources.

These are two concepts that address different issues and operate at different levels within the realm of enterprise IT. Private clouds do not share resources with other users. This type of cloud computing must not be confused with Amazon, DropBox. Microsoft or Google Docs which are all public cloud platforms that share resources with hundreds or thousands of other users.

Why Choose a Private Cloud?

An essential part of a private cloud is virtualization that offers opportunities for reducing infrastructure costs, increasing operational efficiency, and improving deployment flexibility. 

This virtualization creates a virtual machine (VM), a simulated virtual computer that behaves as if it were a computer with its own physical hardware. A server instance deployed with a VM offers many advantages over a physical machine including easy maintenance, application provisioning, availability, and data loss prevention.

The servers of today are designed to house dozens of instances of virtual machines rather than the stand-alone single server that performs just one function. This architecture has redefined technology infrastructure and continues to evolve in how this solution can be delivered to end users. VMs facilitate the implementations of resource pooling and rapid elasticity.

Virtualization Is Not a Private Cloud

Virtualization is not required with SaaS, PaaS, or IaaS. Namely, virtualization is not necessarily presented as a “service” while a private cloud always is. What virtualization accomplishes is making resources virtual without specifying how the virtualized resources are made available to users. In other words, virtualization introduces a mechanism to facilitate implementations of some, but not all, of the private cloud requirements. To equate virtualization to a private cloud is to mistakenly present part of a solution as the solution itself.

Notice that the benefits of virtualization include lower costs, higher efficiency, and flexible deployment to name a few, however these benefits do not translate directly to “capacity on demand,” which is what a private cloud delivers.

Private Cloud Priorities

Cloud Characteristics

The term “cloud” denotes the ability to exhibit the five essential characteristics with one of the three possible delivery methods of a service.* Is the solution you’re considering a “cloud” solution? If so, it will exhibit these five characteristics:

On-demand self-service

A consumer can access computing capabilities automatically and without human interaction with the service provider.

Broad network access

Services are available over the network and accessible through standard cloud client mechanisms.

Resource pooling

Computing resources are pooled to serve multiple clients at a time, with resources dynamically assigned and reassigned according to demand.

Rapid elasticity

Capabilities can scale rapidly up or down commensurate with client demand.

*As stated in the 5-3-2 Principle of Cloud Computing and NIST SP-800-145.

Additionally, a cloud service will be delivered through one of these service models: SaaS, PaaS, or IasS.

Private Cloud Characteristics

Concerning private clouds, the five cloud characteristics outlined above are prioritized differently. Two of the five characteristics remain pertinent but optional in a private cloud setting.

A private cloud is expected to exhibit three or more of the five essential characteristics of cloud computing:

1. Resource pooling
2. Elasticity
3. Self-Service

As mentioned earlier in this article, virtualization is not a private cloud; rather, it’s an important technical component of a private cloud. A private cloud on the other hand encompasses much more than just virtualizing resources.

System Management Now Even More Critical

There is no question that virtualization is an enabling technology in transforming enterprise IT into a cloud environment. The reality is that virtualization is one component of a private cloud solution. Virtualization is nonetheless unequivocally not a private cloud itself. What a decision maker must recognize is that, for building a private cloud, virtualization, resource pooling, elasticity, and self-service model are to be architected as a whole with consistency, compatibility, and integration. Such that the architecture can fundamentally realize the 5-3-2 Principle of Cloud Computing with a predictable and maximal ROI in the long run. The discovery, deployment, configuration, and management of a target resource from bare medal to runtime are all to be based on a common management platform and implemented with a comprehensive system management solution. Further, a consistent user experience in managing physical, virtualized, as well as cloud resources is critical to warrant a continual and increasing cost reduction of on-going technical support and training.

Feasibility of Charging Back

While transitioning into cloud computing, a realistic approach for enterprise IT is to build a private cloud by first transforming the existing infrastructure components and applications into a target cloud environment. With infrastructure components and an application architecture already put in place, a chargeback model may not always be technically feasible or administratively necessary. To charge back, show back, or sponsor an application without a consumption-based cost model is up to an organization’s priorities and therefore not necessarily an architectural requirement of a private cloud.

A Private Cloud Delivers ITaaS

Above all, a private cloud solution offers a technical architecture to strategically advance go-to-market which has become increasingly critical to the survival of a business facing the unpredictable workloads supported by proliferation of mobile devices and triggered by instant data storms in a highly connected business computing environment. IT professionals should know not to confuse the term “virtualization” with what a private cloud really is.. With a private cloud, IT can leverage business opportunities generated by market dynamics and offer a user experience with anytime, anywhere, on any device productivity. The ability of acquiring IT capabilities on demand with a private cloud is in essence a reality of “IT as a Service.”