Analysis: Cloud Computing - Private, Public or Both?

Kyle MacDonald (Profile)
Friday, November 2nd 2012

“A growing number of organisations worldwide are seeing the value of cloud computing as a way of increasing IT flexibility and lowering in-house infrastructure costs. However, achieving the right blend of security, control and cost efficiency depends on choosing the right public or private infrastructure – or the right balance of both,” says Canonical’s Kyle MacDonald, VP Cloud.

Cloud computing is in the ascendancy, with companies of all sizes and sectors getting in on the action. Rapid growth in cloud adoption is highlighted by Gartner’s latest quarterly IT spending report, which predicts a 19% growth in cloud investments during 2012 compared to overall IT spending – which will increase just 3%.

The inexorable shift to the cloud is delivering cost and efficiency gains for businesses across all sectors, from reduced in-house infrastructure requirements and costs, to scalable, on-demand access to networks, compute resources and storage.

With such compelling benefits on offer, the issue for many organisations is no longer whether to do cloud computing – but how.

The Private Public Cloud Conundrum

As a first step towards deployment, businesses typically choose between public and private cloud infrastructure – a decision that is difficult for some companies to make.

As the name suggests, private clouds reside on company owned servers behind the corporate firewall, providing high levels of control and flexibility. By contrast, public clouds are hosted online, delivering virtually unlimited, on-demand access to a wide variety of IT resources at low cost.

So which one is best?

Private Cloud Pros and Cons

Some sectors, such as the financial services and medical industries, require sensitive transactional and customer data to be stored on dedicated servers inside the corporate firewall. If that’s the case in your business, a private cloud is your only option because this personal data can not be compromised.

Even where regulation plays no part, though, many businesses consider private clouds to be more secure than online, multi-tenancy environments as critical systems and data remain inside the business at all times. For this reason, private clouds are often chosen for managing mission-critical applications and data.

Because organisations have full control over private clouds, it’s possible to build in bespoke solutions for fault tolerance, business continuity and disaster recovery. Total control over every aspect of the environment ultimately helps to ensure critical applications and services are always available for staff and customers.

While the benefits of private clouds are clear, there are also some disadvantages to consider. For example, there will always be a capacity ceiling due to the limitations of the physical hardware in the organisation's own server room. What’s more, many private cloud vendors lock customers in with proprietary software, APIs and standards – increasing costs, forcing unwanted upgrades and limiting access to the latest cloud features being developed globally.

Public Cloud Pros and Cons

Where the capacity of in-house infrastructure may be restricted by the capabilities of physical hardware, no limits exist in the public cloud. A range of providers, from Amazon and Rackspace, to Dell and HP give businesses immediate, cost-effective access to online compute and storage resources on demand.

With no need for infrastructure on site, public clouds dramatically reduce hardware and management requirements and costs. What’s more, they support fast deployment of new services and enable scalability on demand.