Infrastructure-as-a-service (IaaS) is a way of consuming virtualised hardware, such as servers, storage and networking via the internet and on a utility basis.
It is the most basic type of cloud computing architecture. IaaS was the fastest-growing segment of the cloud computing market in 2015 and is expected to remain that way through 2016. [Gartner]
IaaS is typically sold in one of three ways: as private cloud, public cloud or hybrid cloud. [See also: ‘what is cloud computing?’]
What is public cloud?
Public cloud is a type of infrastructure-as-a-service where servers and storage are hosted and pooled together by a third-party service provider. Customers can use as much or as little of the pooled capacity as they want.
What is private cloud?
Private cloud is a type of infrastructure-as-a-service where servers and storage are hosted by your own IT department – either in-house or in an outsourced data centre – but presented as a cloud-like service for exclusive use by your own business.
What is hybrid cloud?
Hybrid cloud is an environment that mixes public and private cloud, essentially getting the best from both worlds. [See also: ‘What is hybrid cloud?’]
Who are examples of IaaS providers?
There are a large number of IaaS providers in the market ranging from Microsoft Azure and Amazon Web Services for public cloud services through to mid-sized and boutique players that offer IaaS on a private cloud basis, like Brennan IT.
Why is IaaS the fastest-growing cloud service?
IaaS offers a way for businesses to stop buying, running and maintaining their own IT infrastructure.
Running data centres full of expensive hardware is a model that is increasingly falling out of favour among businesses.
One reason is that IT hardware is becoming commoditised. IaaS provides a way to outsource responsibility for hardware and the operating systems it runs, and to consume it back as a service with utility-like pricing.
IaaS means businesses no longer need to over-provision or overspend on their IT systems to cope with peaks in demand. Rather, they can scale up or down their use of IaaS as demand for compute power increases and decreases.
What advantages does IaaS adoption offer IT shops?
Being freed from administering and maintaining infrastructure means that IT staff can be redirected to work on projects that directly add value to a business’s core products and bottom line.
IT may also be freed from the task of having to provision hardware for new business-led projects, as it can be spun up or down on a self-service basis by anyone with authority.
IaaS may help a business to innovate and bring new products to market faster. It is simple and cost-effective to spin up an environment in which to test and develop ideas. If they fail, the environment can be wound down again with minimal effort and outlay.
How much does IaaS cost?
This depends on a number of factors such as what type of infrastructure you plan to consume as a cloud service, and the amount you use. Depending on the type of IaaS service, charges are typically levied on an hourly or monthly basis, with usually minimal or no upfront costs involved.
This kind of utility billing can be favourable because it converts IT from a capital to an operating expense, and substantially lowers the upfront commitment needed to buy and deploy IT infrastructure.
What choices do I have when setting up IaaS?
While you don’t get to choose the brand of hardware used in an IaaS cloud, you can customise its (virtual) specifications such as the number of CPUs, and the amount of on-board memory and storage space. For a virtual server, you also have a choice of the operating system that you run and what applications or workloads you run on top of it.
In general, the more highly specified the service, the more it will cost per unit of use. Operating system choice can also affect the cost – for example, a virtual server that runs Linux will be cheaper than one running Windows due to licensing costs.
What is the difference between IaaS and PaaS?
The main difference between infrastructure-as-a-service and platform-as-a-service is the line between what the service provider and customer has control over.
In IaaS, the customer controls everything above the physical hardware. They consume virtual resources on that hardware that they can set up in various configurations, with various operating systems, and use to run various applications or workloads.
In PaaS, the customer gives up control over the hardware and the operating system, but retains control over what they can run on it. This makes it particularly well suited to programmers or application developers as they can easily provision an appropriate backend to run their code.
Is IaaS secure?
Cloud providers are well aware that security concerns have traditionally inhibited adoption of the services they offer.
Many providers now offer extensive resources on how to ensure your cloud environment is secure. You can also ask questions about the security of the data centre where the infrastructure is located, as well as the security measures they have taken to keep data in your IaaS environment protected.
You will also need to ensure you can define and apply internal security policies and controls to IaaS as you would for any IT infrastructure you own and operate.
How can I set up my own private IaaS cloud?
Many major vendors offer packages of hardware and software that come pre-integrated and configured to run a private cloud environment.
An alternative is to source your own converged hardware, virtualisation and cloud computing software – which may include the likes of OpenStack, CloudStack, Eucalyptus or OpenNebula – and to build it yourself. However, this is likely to involve some specialist skills, particularly as the size of the environment scales.
How is IaaS changing the way people think about IT infrastructure?
IT infrastructure is a means to an end, and for an increasing number of IT executives it’s something they don’t want to be buying and running in-house in five or ten years. It is costly to buy, administer and maintain, and lean IT shops consider that the staff time spent managing infrastructure could be better spent on activities that elevate IT and add tangible value to the business. There is a concerted effort underway to evaluate just how much of IT can run on an IaaS foundation in the future.