IaaS

Infrastructure as a Service

Pronunciation: EYE-az

Updated October 3, 20262 min read

In short

IaaS (infrastructure as a service) is a cloud model where you rent virtual machines, storage and networks on demand and manage the OS and above yourself.

What is IaaS?

Instead of buying physical servers, you create virtual machines in minutes from a cloud provider's console or API and pay by the second or hour. Amazon EC2, launched in 2006, defined the model; Azure Virtual Machines and Google Compute Engine are the main alternatives, and providers such as DigitalOcean and Hetzner offer simpler virtual servers.

Alongside compute, IaaS includes block storage for disks, object storage for files, virtual private networks, firewalls, load balancers and public IP addresses. You choose the operating system, install the software, apply security patches and configure scaling, which gives the most control of any cloud model.

IaaS is the bottom layer of the cloud service models: above it, PaaS manages the runtime for you and SaaS delivers finished software. It suits workloads that need specific operating systems or software, full control over networking, lift-and-shift migrations from data centers, and teams that automate their infrastructure with tools such as Terraform.

A common misconception is that moving to IaaS automatically makes a system cheaper or more reliable. A virtual machine left running all month, oversized instances and unused disks quickly add up, and a single server in the cloud fails just like one at home. Autoscaling, multiple availability zones and cost monitoring have to be designed in.

Key takeaways

IaaS rents virtual machines, storage and networks on demand.
You manage the operating system, software, patches and scaling.
Amazon EC2, launched in 2006, defined the model.
It is the bottom layer, below PaaS and SaaS, with the most control.
Savings and reliability depend on good design and cost monitoring.

Example

Starting a virtual machine on AWS from the command linebash

# Launch one small Linux server
aws ec2 run-instances \
  --image-id ami-0abcdef1234567890 \
  --instance-type t3.micro \
  --key-name my-key \
  --security-group-ids sg-0123456789abcdef0 \
  --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=web-1}]'

# From here on, the OS, updates and software are yours to manage
ssh -i my-key.pem ec2-user@<public-ip>

Readers ask

What are examples of IaaS?

Amazon EC2, Azure Virtual Machines, Google Compute Engine, DigitalOcean Droplets and Hetzner Cloud servers, along with the storage and networking services that come with them.

What do I manage in IaaS?

The provider manages the physical hardware, data centers and virtualization. You manage the operating system, runtime, applications, data, security patches and configuration.

Is a virtual private server (VPS) IaaS?

Yes. A VPS is a simple form of IaaS: a virtual machine you rent and manage yourself, usually at a fixed monthly price.

Often compared

IaaS vs PaaSIaaS rents you raw infrastructure like virtual machines that you manage yourself, while PaaS runs your code and handles the servers, OS and scaling for you.