What is a Public Cloud, and What is a Private Cloud? – What On Earth Is Cloud Part 5/7

If you’ve been following along with our series “What on Earth Is Cloud” you’ve probably seen a mention of Private Cloud and Public Cloud quite a few times and, I did promise to get around to explaining these in more detail.  If you haven’t checked out the series from the beginning you can very easily do so by clicking here – but if you just want the scoop on Public vs Private then please do read on.

Like any technology there is no “cookie cutter” approach to anything, especially when many business models have been built on entrepreneurial spirit, a hodge podge of ideas, technologies and systems and processes.  If this sounds like your organisation then there is a very high likelihood that cloud can be an exciting opportunity to scale your operation but also a very challenging shift in the way you operate.

Public Cloud, like anything else with the name public (public transport, public toilets, public library) means just that.  A service or utility that is generally available to the public. Of course behind the scenes there’s a little more to it than that but so far as the definition goes, a public cloud service provider isn’t restricted to a certain person or group but rather provides a mass service generally to anyone and everyone.  Like any public service it doesn’t necessarily suit everyone’s needs so the provider offers the service “as is” and generally doesn’t offer too many tailoring options.

Let me break it down for you.  If you’ve ever used Google’s Gmail, Microsoft’s Hotmail or Apple’s MobileMe you are using a public cloud email service.  If you’ve ever bought a book from Amazon or a song from iTunes you’ve used a public cloud service and if you’ve ever used a public library.. you’ve used a public library

Public cloud services for many are fantastic because they’ve taken an idea or a concept and figured out a way to get it out to millions of people at once generally at a remarkably lower cost compared to developing/building/maintaining your own IT system.

That doesn’t necessarily mean millions of people have access to your emails, personal files and music collection but it does mean that there are some security limitations and it severely limits the ability of an organisation to customise IT services to fit their particular model.  Imagine being the CEO of a company who has decided he really wants a particular piece of software to act or behave a certain way when interacting with customers.. so he writes himself an email to Google requesting the change… and.. he gets no response.  Why?  Google aren’t about to change their 1 size fits all cloud offering to fit your little operation (and if you’re Google.. almost every operation is a little operation in comparison).

Like anything, there is always a downside and for many organisations the downsides of Public Cloud are far too significant for them to take the risk.  Thus, “private cloud” refers to services that are limited to a specific organisation, group of people with authorised access or group of organisations again, authorised to access a set of IT services.

If you’re running a server or servers in a room in your office, in a lot of ways you are already running your own private cloud.  By restricting access to only those immediately involved in your business you have some substantial benefits such as security, choice of the location of your data (earlier in this series we discussed the risks of offshoring your customer’s or your own data to other countries) and flexibility to customise your IT solution to fit your business model.

Private Cloud refers to having that security and flexibility but instead of keeping it in your own office, you choose a data center and a service provider to deliver those IT services to you remotely from the cloud.

Many organisations may find that they benefit from both.  If you’re part of a large ASX200 or Fortune 500 company it’s unlikely you’ll hand over your critical systems into the public cloud, perhaps with the exception of email (Microsoft and Google are pushing incredibly hard to have organisations move into their respective cloud mail and document offerings and have had varied success) and many just can’t afford the risk of offshoring to a public service provider.  I spoke with a large Australian charity organisation last year who informed me in no uncertain terms that if they were to go cloud they would want a fully dedicated line only accessible by them running from their office to the data center, 24×7 secure access, absolutely no other organisation was allowed access to that area of the data center.  This is the ultimate private cloud and obviously prohibitive in cost to most organisations but it does demonstrate why public cloud simply can’t provide for all companies.

In smaller business, a combination of public cloud and private cloud already exists.  Many are using Internet Banking (a form of public cloud) while hosting their website online (another form of public cloud) but keeping their records and corporate data in their office on a server (a form of private cloud).  In the future, that organisation might choose to move their corporate data into a data center (still a private cloud).

The challenge for organisations moving forward is the record keeping and “mapping” of where their critical IT services reside.  For example, today I noticed that this blog wasn’t working correctly and was taking a long time to load.  I could swear that it was hosted in our data center (I Know IT‘s private cloud), you see we have so many different services such as websites, blogs, sharepoint, CRM and other technologies that it can be hard to keep track.  I almost began the internal resolution process when I quickly checked our documentation to make sure I knew exactly where the blog was hosted and as it turns out it is with a 3rd party.  Rather than resolve the matter internally I now need to contact a 3rd party to resolve the problem.

Therein lies the challenge for organisations who will be likely to use combinations of different service providers in the future.  Is it public? is it on premise (a form of private)? or is it private (hosted in a data center)? - these questions will become common terminology amongst IT support providers and IT administrators within an organisation and the more services that are farmed off to various clouds be it public or private, the more administrative time and dedication to security is required.

Discovering whether to go public or private will largely depend on the security and flexibility requirements of your organisation and of course cost or value of the solution.   Public Cloud has the economy of scale whereas private cloud is, or should be, developed based purely on the needs of the organisation and their budget.

Going Cloud can be complex and many questions go beyond the scope of this series.  I’m open to comments or questions on this and you can contact me either by commenting below on this article or contacting me through I Know IT

Click here for the next article in the series “Should I Shift to The Cloud?”