Private clouds are cloud environments solely dedicated to the end user, usually within the user’s firewall. Although private clouds traditionally ran on-premise, organizations are now building private clouds on rented, vendor-owned data centers located off-premise.
All clouds become private clouds when the underlying IT infrastructure is dedicated to a single customer with completely isolated access.
How do private clouds work?
Private clouds rely on a handful of various technologies, but understanding how virtualization works is the key to understanding how private clouds work. A private cloud uses virtualization technology to combine resources sourced from physical hardware into shared pools. This way, the cloud doesn’t have to create environments by virtualizing resources one at a time from a bunch of different physical systems. A scripted IT process can just grab all those resources from a single source—like a data supermarket.
Adding a layer of management software gives administrative control over the infrastructure, platforms, applications, and data that will be used in the cloud by helping cloud admins track and optimize use, oversee integration points, and retain or recover data. When the final automation layer is added to replace or reduce human interaction with repeatable instructions and processes, the self-service component of the cloud is complete and that bundle of technologies is now a private cloud.
Building a private cloud
Cloud infrastructure refers to the components needed for cloud computing. The basic elements of cloud infrastructure are the same whether you have a private cloud, public cloud, or a combination.
All clouds require operating systems—like Linux®—but the infrastructure can include a variety of bare-metal, virtualization, or container software that abstract, pool, and share scalable resources across a network.
You can build a private cloud on your own using resources dedicated solely to you, or use prepackaged cloud infrastructure like OpenStack®.
Managed private clouds
With private clouds, you’re completely responsible for all costs at all times. You staff, manage, and maintain all underlying infrastructure. But private clouds can also be delivered by cloud providers as part of a managed private cloud approach.
Managed private clouds let customers create and use a private cloud that’s deployed, configured, and managed by a third-party vendor. It’s a cloud delivery option that helps enterprises with understaffed or underskilled IT teams provide better private cloud services and infrastructure to users without the day-to-day complexities of managing a private cloud themselves.
The bare-metal IT infrastructure used by cloud providers can also be abstracted and sold as Infrastructure-as-a-Service (IaaS), or it can be developed into a platform sold as a Platform-as-a-Service (PaaS).
Why use private clouds?
Private clouds are the ideal solution for IT leaders who want to make enterprise resources available on-demand, but can’t (or don’t want to) move to the public cloud. This can be due to security policies, budgets, compliance requirements, or regulations, like those that define the healthcare and financial service industries.
Companies in these industries use encryption protocols and firewalls to secure their IT systems, but private clouds add an extra level of security—compared to public clouds—because access is limited.
Whether or not you invest in private cloud infrastructure also depends on the workloads that need to be supported. Traditional, stateful workloads are well supported by enterprise virtualization products. But stateless, loosely coupled workloads—typically found in development, research, and telecommunications (particularly network functions virtualization)—are better supported by private clouds.
Private cloud benefits
Private clouds reduce instances of underused capacity. They allow the enterprise to automatically configure and reconfigure resources in any way it wants, since those resources aren’t restricted by their physical installations.
Private clouds provide additional benefits, such as:
- Increased infrastructural capacity to handle large compute and storage demands
- On-demand services using self-service user interfaces and policy-based management
- Efficient resource allocation based on user needs
- Increased visibility into resources across the infrastructure
Private cloud storage
Big data and the Internet of Things (IoT) have made private cloud storage very important to businesses, particularly in an era where it can difficult to appraise the value of a byte until long after it was created. Private clouds use something called software-defined storage (SDS) to archive and sort data. One of the more common SDS solutions for private clouds—particularly those deployed using OpenStack®—is Ceph. Ceph is the open source project behind Red Hat Ceph Storage, and it works well with clouds because it unifies object, block, and file storage into a single resource pool.