A firm definition of the ‘private cloud’ is at best transient and at worst, well, cloudy. Kevin Gruneisen sets out a simpler definition – what a private cloud is not.
Microsoft explains on its Technet website that “A private cloud is a cloud that is provisioned and managed on-premises by an organisation. The private cloud is deployed by using an organisation’s own hardware to leverage the advantages of the private cloud model.”
On the face of it, quite straightforward. Not a bit of it. The Microsoft definition is one of nearly 4000 thrown up by a Google search – each with its own slant.
The reality according to Gartner’s research director for virtualisation and cloud, Aneel Lakhani, is “there is zero consensus on what enterprise IT considers private cloud to be. Installations labelled ‘private cloud’ now range from data centres having several virtualised machines, to having some very basic ability to automate processes, to possibly having some self-service components.”
The truth is, it’s much easier to work out what a private cloud is not – and, helpfully Gartner produced a report on exactly that, as far back as 2012. It is definitely worth revisiting some of its key points:
Private cloud is not virtualisation. The point here is that while virtualisation is a feature of private cloud computing, virtualising servers and infrastructure alone does not create a private cloud.
Gartner gets close to a definition in its report by telling us “private cloud computing is a form of cloud computing that is used by only one organisation, or that ensures that an organisation is completely isolated from others.”
Private cloud is not just about cost reduction. The key benefit of a private cloud is principally agility, speed to market, ability to scale to varying demand or to pursue short windows of opportunity, and the opportunity for business units to experiment.
Cost reduction comes from the standardisation and replication of process delivered by the cloud. Automation is paramount – let humans do the work, it takes days or months and is error prone. Let computers do the work it gets done faster, with fewer errors and can be better tracked and audited. This should drive down costs.
However, Investment is required, which is why financial justification is so important. Some private clouds could be classified as OpEx spend, which can be a game changer for organisations strapped for CapEx.
Private cloud is not necessarily on-premises. Crucially the term ‘private’ refers to privacy rather than location. This means as long as the network is private it satisfies the requirements of a private cloud.
The reality is if your private network is physically hosted, in part, by a public cloud provider, you have a Hybrid Cloud.
Private cloud is not only Infrastructure as a Service (IaaS). IaaS provides, as the name suggests, the basic data centre resources in a way that is easy to consume, but doesn’t change the detail of IT. Platform as a Service (PaaS) on the other hand, is all about the detail – it allows apps to be created, hosted and distributed that are altogether different from old desktop applications.
Private cloud is not always going to be private. We have already alluded to this when discussing on-premise. Given the enhanced service levels and economies of scale that public cloud providers can pass on, most cloud deployments will inevitably end up being Hybrid Cloud solutions.
Whatever private cloud is, or is not, your cloud strategy deserves attention and constant review. As my colleague Mike Martin said last year what the buzz around cloud computing doesn’t tell you is this: Getting to the point where you realise the benefits is not easy.