When deciding on cloud infrastructure, there are many choices to be made, but the most fundamental is whether to opt for public cloud or private cloud infrastructure. There’s no right choice that fits every organization or project — it depends what your organization wants to achieve and its goals for the deployment. I’d like to briefly discuss what the difference is between the public and private cloud and the respective advantages of each.
First, both public and private clouds use essentially the same technology. There is an underlying layer of physical infrastructure — servers and networking hardware. The servers run a basic operating system and virtualization software. The virtualization software creates and manages virtual servers that are typically known as cloud servers. Both modalities allow servers to be created and destroyed quickly along with the other benefits of virtual infrastructure.
The essential difference between public and private cloud infrastructure lies in who owns and manages the underlying physical infrastructure. In a public cloud, the physical servers and the virtualization layer are owned and managed by a cloud provider. Users have little insight into what is happening beneath the cloud servers they deploy. Many different clients deploy workloads on the same physical infrastructure, although they have no access to the virtual environment of other users.
The major benefits of the public cloud are the outsourcing of physical hardware management, maintenance, and housing to a third party. The client manages the virtual servers that form their virtual network, but they don’t have to worry about the underlying hardware. For many companies, the public cloud is the most economical and efficient cloud modality — there’s no upfront capital investment for servers — but it’s not without its limitations. Giving up control of the underlying physical layer means just that: the user has no control over the hardware that’s used, how the networks are designed, and how well the system as a whole performs. And, of course, sensitive data is stored on the servers of a third party. Many companies prefer to keep sensitive data on systems that they own and control.
Which brings us to private clouds. On private clouds, the underlying physical hardware is owned and managed by the client who uses the cloud — although it may well be collocated and managed by a third-party data center provider or a specialist private cloud vendor. The most important point is that only that client’s data will run in that private cloud, and only they will have access to it.
As you might imagine, the benefits and potential weaknesses of private clouds are the mirror of those we’ve described for the public cloud. Private cloud users pay upfront for their hardware, and they pay directly for the management, housing, and maintenance of their servers. If the private cloud is in a private data center, they have to invest in building the infrastructure, otherwise they pay a data center or private cloud provider to do it for them. With a private cloud, organizations have more control over the hardware and the software it runs than a public cloud platform can offer. The infrastructure and software stack can be designed and deployed to meet the specific requirements of the business, and, of course, the data on a private cloud is always under the control of the organization — something that’s of critical importance to many organizations.
So which is the best choice for your organization? I’m going to suggest that in the general case the answer could be both and neither. Each cloud modality has specific strengths, and many organizations benefit from embracing the virtues of both modalities. Hybrid clouds, which combine public and private cloud infrastructure, allow organizations to leverage all of the flexibility of the public cloud for workloads and storage scenarios deemed suitable for outsourcing, while maintaining a private infrastructure for more sensitive projects and data.
The range of options available to companies — private, public, hybrid — allows them to deploy the cloud infrastructure that best meets their specific needs.