According to the National Institute for Standards in Technology (NIST), cloud computing 
as a whole provides a measured and on-demand self-service, with pooled resources, broad network access, and the rapid and elastic scaling of resources. And it’s on the rise – particularly with corporate clients.
But there’s still some confusion about its various flavours. In this article, we’ll look at its private aspect.
Some Basics, First
In a private cloud, an online provider of computing resources (i.e., the cloud) provides computational power as a service, operating in a virtualised (software or memory-based, rather than physical hardware) environment. The private aspect comes in as the service is only made accessible to a single organisation – the specific client who subscribes to it.
Ring Fencing
One of the defining characteristics of a private cloud is ring fencing, or the setting up of firewalls and access controls around the cloud resource, to confine its use to a single organisation. This is often achieved in tandem with increased network security protocols.
This situation contrasts with a public cloud, in which multiple clients can gain access to virtualised resources and services, which originate from the same bank of servers, set up on public networks.
In the case of a ring-fenced private cloud, the client organisation can operate in the assurance that their confidential or sensitive data can be stored and processed under conditions of greater security.
Private – But Not In-House
The bank of physical hardware from which a private cloud draws its computing power may be hosted on-site at the client organisation’s offices, or externally. And access to it may be gained via securely encrypted connections on public networks, or through private leased lines. Connections to the cloud must be made from behind the safety of the client’s firewall.
Contrary to popular belief, a private cloud doesn’t have to based inside an organisation’s own data centre. Many service providers market off-premise clouds, with private resources dedicated to a contracted client. Resources don’t have to be shared with other customers, and there’s no multi-tenant pooling of resources.
Service Offerings
Infrastructure as a Service or IaaS is the most commonly recognised form of private cloud, with virtualised environments acting as extended network infrastructures. IaaS may be considered the baseline level in provision of data centre resources.
There are other options, including Software as a Service (SaaS), and Platform as a Service, or PaaS.
Platform as a Service has public and private forms, with the latter having its application development facilities hosted in the client’s on-site data centre or in an environment hosted by the service provider. Using PaaS, enterprises can develop specialised applications which are tailored to run on the cloud infrastructure.
Benefits
Heightened security and the restriction of resource access to a single client give private cloud the edge over public, in the eyes of many Chief Security Officers and system administrators. In addition, the single client restriction gives an organisation greater control over the configuration and management of the cloud resource, which may be customised to suit the organisation’s particular needs.
As resources in a private cloud may be directly and responsively allocated to individual teams and departments in an organisation, there will be corresponding increases in working efficiency, and reductions in operational costs. The cost savings are an improvement over the often unused capacity of a traditional corporate LAN, but typically not as much as in a public cloud, due to the increased overhead of managing the private resource.
In the event of parts of the physical network infrastructure failing, the virtualised spaces defined by a private cloud provide a degree of redundancy and resilience – even when servers and other network elements are hosted internally. With infrastructure hosted by a third-party cloud provider, the degree of failure protection is even greater.
With some vendors, unanticipated spikes in network demand can be met by temporarily porting non-sensitive data and applications to a public cloud – a process known as cloud bursting.
Drawbacks?
Public clouds are notable for the economies of scale they offer by managing hardware from a central point. These potentially large savings may be lost in a private cloud, especially one where resources are being managed and configured, in-house.
With the client’s own IT division managing a cloud, capital expenditures, staff costs, maintenance and management will all take a bite from the budget. So too will the purchase of tools and software for cloud implementation and management, and virtualisation tools.
Customers should also be wary of cloud service providers who use a collocation facility for outsourcing their data centre operations, or use Virtual Private Networks (VPNs) to separate clients using resources from a common pool.
Who’s It For?
Private cloud is best suited to organisations that have unpredictable or wildly varying computing requirements, in which direct control over the environment is key to operations.
For example, shared computing environments (such as those in a public cloud) would be unsuitable for enterprises with service contracts that mandate specific uptime requirements, or for businesses having particular security concerns or mission-critical workloads.
Beyond Privacy
The cloud bursting facility offered by some hosts is just one instance of the move beyond private cloud.
Increasingly, organisations are being encouraged to move non-sensitive data and functions to public clouds permanently, while retaining their confidential or mission-critical information in the private realm. This is known as hybrid cloud deployment – a “best of both worlds” solution – and is seen as the future of the cloud, for corporate users.
Kerry Butters
Kerry is a published author and writer on all things tech, corporate tech, data centres, SEO, webdesign & more for some of the world’s leading sites.