What is IaaS (Infrastructure as a Service)?

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Infrastructure as a Service (IaaS) in plain language

A cloud virtual machine gives a team control over its software environment without ownership of the underlying physical server. That control comes with work: patching the guest system, restricting network access and maintaining the application.

Shared responsibility does not mean responsibility is vague. Write down who handles each layer and how it is verified. Managed databases or application platforms may shift additional duties to a provider, but they are different service boundaries.

How it works

Provision the required capacity
Select a compatible machine size, operating-system image, storage and network arrangement.
Configure the guest environment
Install the required software and updates. Keep credentials separate from machine images and limit exposed ports.
Maintain and recover
Monitor the service, patch it and test restoration. Document who responds to an unavailable instance.

Illustrative example · Fictional data

Running a fictional reporting application

Input: A team needs a specific supported runtime and scheduled reports, so it chooses a cloud VM.
Process: Create the VM, deploy the runtime and application, restrict inbound access and schedule a backup with a restore test.
Expected output: A configured reporting server with named owners for guest patches, application updates and recovery.
How to check it: Provider maintenance of physical hardware does not patch the application. A completed backup job is also not proof that the report data can be restored.

Where it helps

Hosting software that needs guest-system control.
Creating isolated test environments with known configurations.
Migrating suitable existing workloads while retaining system-level control.

Where the operational boundary changes

Physical server: The organisation also handles hardware ownership and its operating environment.
IaaS VM: The provider operates underlying infrastructure; the customer operates the guest system and workload.
Managed platform: The provider manages more of the runtime stack, with less customer control over those layers.

Common pitfalls

A public IP address and permissive firewall can expose an otherwise well-maintained VM.
Unused storage and retained snapshots can continue to incur charges.
A VM image is not automatically compatible with every instance architecture.

Put the idea to work

Try it yourself

Create a two-column ownership list for hardware, guest patches, application updates, user access and data restoration. Mark any item whose owner has not been assigned.

Common questions

Does IaaS include operating-system maintenance?

The guest operating system is generally the customer’s responsibility. Check the specific service and any additional managed-service agreement. That usually includes patching, hardening, antivirus and monitoring of the guest system. Managed offerings or automation tools can reduce this work but do not remove the need for ownership.

Can containers run on IaaS?

Yes. A VM can host a compatible container runtime, but someone still needs to operate that VM and runtime. Many teams instead use a managed container or Kubernetes service, which shifts part of that operational work to the provider while keeping container portability.

Does a provider backup option remove recovery planning?

No. Decide what to back up, how long to retain it and how to test restoration against the application’s needs. Define recovery-time and recovery-point targets, store copies in a separate location or account and run restore drills regularly, because an untested backup may fail when needed.

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