As organizations look to building efficient, scalable web applications, they often turn to the cloud to satisfy their needs. Given that the leading infrastructure-as-a-service (IaaS) providers Amazon Web Services (AWS), Rackspace, and Windows Azure are best known for their public cloud solutions, it's not surprising that some businesses never consider private clouds because they know too little about them. While public clouds offer similar security to private ones, and may be certified for compliance with HIPAA, Sarbanes-Oxley, or PCI requirements, not all companies are comfortable yet with losing what they perceive as a level of control of their data. For them, a private cloud may be a first step toward “cloudifying” their organization’s data centers. But before they consider a private cloud as an alternative, businesses first need to understand just what a private cloud is.
The definition of private cloud is not as clear-cut as you might think. Because it's a cloud, it provides hosted services to an organization that can scale to meet the demands of one or many applications. Because it's private, its resources are not shared, as can be the case with public cloud platforms. Private clouds are API-driven, have metered usage, and allow self-service or highly automated provisioning. RightScale myCloud lets organizations create and manage private clouds using popular cloud infrastructure software such as CloudStack and OpenStack.
A Private Cloud Can Be Off-Premises
Cloud infrastructure providers such as Rackspace and Windows Azure maintain that a private cloud can be any server environment reserved for a single organization's use, even if it's off-premises. By that definition, you could host a private cloud on a public platform, as long as no other organization shares the same resources. However, any data you put in the hands of a third party may be slightly more exposed to subpoena by law enforcement agencies than data you host internally.
You might also consider hosting your private cloud on your own hardware behind your own firewall, but allowing it to be managed by a third party, thereby retaining one of the great benefits of cloud computing — freeing up your internal IT staff. While this practice clearly preserves the private cloud, it has a slight potential to reduce the degree of privacy.
Given these benefits, why shouldn't everyone choose a private cloud? One reason can be cost. If you wish to maintain dedicated hardware resources, you're going to have to pay for your hardware up front and maintain your cloud infrastructure full time, rather than being able to take advantage of the elastic nature of usage and costs with a public cloud. But a private cloud can also sometimes be more economical than using public cloud. There is really no simple answer as to which is more cost efficient. Recent Forrester research also uncovered some interesting nuances in private cloud deployment that are worth considering.
If your organization has adequate IT resources, you may already be considering a private cloud as an alternative or complement to public cloud projects. When you do, take a look at how RightScale can help you manage it.