Several years ago cloud computing became the hottest thing in IT. You couldn’t read an article or product description without being smothered with ‘cloud’ every other sentence. In fact, many organizations renamed their product and service offerings to include cloud. If you didn’t have ‘cloud products and services’, you were going to lose business.

I’ve noticed that there’s still a surprising amount of IT people that don’t fully comprehend what cloud computing means. Is it a location or a concept? Are there different types and layers of cloud computing? Lets see if we can explain a few of the more common options…

The concept of cloud computing

Cloud computing is a concept, not a location. With cloud computing you will be using a service where some part of the chain is not managed by yourself. Instead a third party will be responsible for some of the day to day operations.

Take email as an example. Traditionally you would have an Exchange server in your own datacenter. You would manage the whole chain: from datacenter facilities via servers to the email application on the client side. With cloud computing services like Office 365, Microsoft takes care of everything. You, the customer, only needs to point the DNS records and clients to the Microsoft datacenters and Microsoft will take care of the rest.

This gives you three benefits:

• You no longer need to worry about keeping the whole application chain running. In case you’re a small company that can’t afford an Exchange specialist, this means you save costs and have a better application experience at the same time (since you wont do a poor job due to lack of skills or experience).
• Predictable costs. Your own Exchange environment is refreshed every 5 years, meaning you need to do a bulk investment in new storage, servers and application licenses. Cloud computing is billed with a monthly recurring cost. This means less upfront investment for the business.
• Agility. This agility is derived from a high degree of automation in cloud computing: you request services via a portal and in the background some processes make sure the services are delivered. This results in 24/7/365 low provisioning times, which allows you to respond to changing business requirements rapidly.

DIY vs IaaS vs PaaS vs SaaS

Okay, so cloud computing is an operating model. You’re basically assigning responsibilities to different parties. In the DIY “run your own datacenter” model you are responsible for all of the infrastructure. Office365 is a Software as a Service or SaaS application: Microsoft is responsible for everything required to keep the application operational. There are many intermediate steps, with PaaS and IaaS as the most notable examples.

In IaaS or Infrastructure as a Service, the cloud provider will build and maintain the infrastructure necessary to run your virtual machines or containers. That’s data center facilities (power/cooling/physical security), storage, compute/servers and the hypervisor layer on top of that.

With PaaS or Platform as a Service, some additional responsibilities move towards the provider. In a database PaaS solution the cloud provider could additionally manage the OS and the database software, enabling you to store a database and use it on the fly without having to worry about SQL updates.

There are plenty of providers that are willing to customize these standard services and for example, offer you IaaS with OS management included.

Public, private and hybrid cloud

When using public cloud services you are sharing hardware and software with potentially many other customers. Because there’s many customers using the same pool of resources, this means you can usually grow your environment quite rapidly. Peaks and dips in the resource utilization can also be smoothed out by someone else: if you turn off a R&D server at night, someone else on the other side of the world can use these resources for the increased virtual desktop load. This keeps costs low.

With private cloud services the infrastructure is typically dedicated for your company. I say typically, because you can’t avoid sharing some common components like connectivity. The advantage of private cloud is the improved security and the flexibility to customize the infrastructure to your requirements. The downside is that its usually somewhat more expensive to build and run a private cloud: if you don’t use 100% of the available resources, they are wasted.

The hybrid cloud is a combination of public and private cloud and the ability to move workloads between public and private cloud on demand. The kicker is in the latter part of the previous sentence: just having some virtual machines running on your own hardware and some other machines running at Azure, doesn’t make your infrastructure a hybrid cloud. As we discussed at DellEMC World last week in Austin, the true power of the hybrid cloud is in being able to move workloads between the types of clouds when needed.

A public cloud is always located at a service provider location: there will be multiple customers using the hardware. Notable examples are Azure and AWS: if you provision virtual machines in Azure, they run in one of the Azure data centers across the world.

Private cloud gives you the option to either run the systems in your own data center or in the service provider data centers.

My thought on clouds

Public, private and hybrid clouds, on-premises and off-premises… they’re here to stay. Public and private cloud have quite different characteristics. Fortunately with hybrid cloud technologies emerging (like Azure Stack in 2017), its getting easier to exploit the benefits of both types.

Be mindful of what you are purchasing though! And please don’t just go to the cloud because everyone is doing it. Too often I hear people shout “we want to go to the cloud!”, with their motivation being “Because.. cloud!”. You can be in for one hell of a surprise if your organization is not mature enough to cope with the downsides of cloud computing. More on that in a future post…