IaaS - Infrastructure as a Service

Complete guide to Infrastructure as a Service (IaaS), covering virtual machines, networking, storage, and hands-on examples with AWS EC2, Azure VMs, and Google Compute Engine.

Infrastructure as a Service (IaaS) is the most fundamental cloud service model. It provides virtualized computing resources over the internet, giving you the building blocks of IT infrastructure — compute, storage, and networking — without the burden of managing physical hardware.

What IaaS Provides

┌─────────────────────────────────────────────────────────────┐ │ IaaS RESPONSIBILITY MODEL │ ├─────────────────────────────────────────────────────────────┤ │ │ │ YOU MANAGE: │ PROVIDER MANAGES: │ │ ┌─────────────────┐ │ ┌─────────────────────┐ │ │ │ Applications │ │ │ Virtualization │ │ │ │ Data │ │ │ Physical Servers │ │ │ │ Runtime │ │ │ Physical Storage │ │ │ │ Middleware │ │ │ Physical Networking │ │ │ │ Operating System│ │ │ Data Center │ │ │ └─────────────────┘ │ │ Power & Cooling │ │ │ │ │ Physical Security │ │ │ │ └─────────────────────┘ │ └─────────────────────────────────────────────────────────────┘

Core IaaS Components

1. Compute (Virtual Machines)

Example

# AWS EC2 - Launch a virtual machine aws ec2 run-instances \ --image-id ami-0c55b159cbfafe1f0 \ --instance-type t3.large \ --key-name my-key-pair \ --security-group-ids sg-0123456789abcdef0 \ --subnet-id subnet-0123456789abcdef0 \ --count 1 \ --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=WebServer}]' # Azure Virtual Machine az vm create \ --resource-group myRG \ --name myVM \ --image Ubuntu2204 \ --size Standard_D4s_v3 \ --admin-username azureuser \ --generate-ssh-keys # Google Compute Engine gcloud compute instances create my-instance \ --zone=us-central1-a \ --machine-type=n2-standard-4 \ --image-family=ubuntu-2204-lts \ --image-project=ubuntu-os-cloud \ --boot-disk-size=100GB

2. Storage

bash example

# AWS EBS (Block Storage)
aws ec2 create-volume \
  --availability-zone us-east-1a \
  --size 500 \
  --volume-type gp3 \
  --iops 3000 \
  --throughput 125

# Attach to instance
aws ec2 attach-volume \
  --volume-id vol-0123456789abcdef0 \
  --instance-id i-0123456789abcdef0 \
  --device /dev/sdf

3. Networking

bash example

# Create a VPC
aws ec2 create-vpc --cidr-block 10.0.0.0/16

# Create subnets
aws ec2 create-subnet \
  --vpc-id vpc-0123456789abcdef0 \
  --cidr-block 10.0.1.0/24 \
  --availability-zone us-east-1a

# Create Internet Gateway
aws ec2 create-internet-gateway
aws ec2 attach-internet-gateway \
  --internet-gateway-id igw-0123456789abcdef0 \
  --vpc-id vpc-0123456789abcdef0

IaaS Providers Comparison

Feature	AWS (EC2)	Azure (VMs)	GCP (Compute Engine)
Instance Types	400+	300+	150+
GPU Support	P4, G5, Inf2	NCv3, NDv2	A2, T4
Max vCPUs/VM	448	416	416
Max Memory	24 TB	12 TB	12 TB
Per-second billing	Yes	Yes	Yes
Spot/Preemptible	Up to 90% off	Up to 90% off	Up to 91% off
Bare Metal	Available	Available	Available

IaaS Use Cases

Web Hosting: Deploy web servers with full OS control
Development/Testing: Spin up and tear down environments quickly
Big Data: Process large datasets on powerful instances
Disaster Recovery: Replicate on-premises infrastructure to cloud
High-Performance Computing: Run scientific simulations on GPU clusters

Real-World Deployment Example

Example

# Terraform IaaS deployment resource "aws_instance" "web_server" { ami = "ami-0c55b159cbfafe1f0" instance_type = "t3.large" subnet_id = aws_subnet.public.id root_block_device { volume_size = 100 volume_type = "gp3" encrypted = true } vpc_security_group_ids = [aws_security_group.web.id] user_data = <<-EOF #!/bin/bash apt-get update apt-get install -y nginx systemctl start nginx systemctl enable nginx EOF tags = { Name = "production-web" Environment = "production" } } resource "aws_ebs_volume" "data" { availability_zone = "us-east-1a" size = 500 type = "gp3" encrypted = true }

Interview Questions

What is IaaS and what components does it include?

IaaS provides virtualized computing resources over the internet — primarily compute (VMs), storage (block/object), and networking (VPCs, load balancers). Users manage everything from the OS upward, while the provider manages physical infrastructure.

Compare IaaS with traditional on-premises infrastructure.

IaaS eliminates hardware procurement (minutes vs weeks), offers pay-per-use pricing (no CapEx), provides elastic scaling, and removes maintenance burden. However, you lose some control over physical hardware and may face higher long-term costs for steady workloads.

When would you choose IaaS over PaaS?

Choose IaaS when you need full control over the operating system, require custom software installations, need specific kernel configurations, or are migrating existing applications via lift-and-shift with minimal changes.

What are spot instances and when should you use them?

Spot instances are spare cloud capacity available at up to 90% discount but can be interrupted with short notice. Use them for fault-tolerant workloads like batch processing, CI/CD pipelines, data analytics, and rendering — never for stateful production databases.

Explain the networking components of IaaS.

VPC (isolated virtual network), subnets (network segments), internet gateways (public internet access), NAT gateways (outbound-only for private subnets), security groups (instance firewalls), and route tables (traffic routing rules).

What IaaS Provides

Core IaaS Components

1. Compute (Virtual Machines)

Example

2. Storage

bash example

# AWS EBS (Block Storage)
aws ec2 create-volume \
  --availability-zone us-east-1a \
  --size 500 \
  --volume-type gp3 \
  --iops 3000 \
  --throughput 125

# Attach to instance
aws ec2 attach-volume \
  --volume-id vol-0123456789abcdef0 \
  --instance-id i-0123456789abcdef0 \
  --device /dev/sdf

3. Networking

bash example

# Create a VPC
aws ec2 create-vpc --cidr-block 10.0.0.0/16

# Create subnets
aws ec2 create-subnet \
  --vpc-id vpc-0123456789abcdef0 \
  --cidr-block 10.0.1.0/24 \
  --availability-zone us-east-1a

# Create Internet Gateway
aws ec2 create-internet-gateway
aws ec2 attach-internet-gateway \
  --internet-gateway-id igw-0123456789abcdef0 \
  --vpc-id vpc-0123456789abcdef0

IaaS Providers Comparison

Feature	AWS (EC2)	Azure (VMs)	GCP (Compute Engine)
Instance Types	400+	300+	150+
GPU Support	P4, G5, Inf2	NCv3, NDv2	A2, T4
Max vCPUs/VM	448	416	416
Max Memory	24 TB	12 TB	12 TB
Per-second billing	Yes	Yes	Yes
Spot/Preemptible	Up to 90% off	Up to 90% off	Up to 91% off
Bare Metal	Available	Available	Available

IaaS Use Cases

Web Hosting: Deploy web servers with full OS control
Development/Testing: Spin up and tear down environments quickly
Big Data: Process large datasets on powerful instances
Disaster Recovery: Replicate on-premises infrastructure to cloud
High-Performance Computing: Run scientific simulations on GPU clusters

Real-World Deployment Example

Example

Interview Questions

What is IaaS and what components does it include?

Compare IaaS with traditional on-premises infrastructure.

When would you choose IaaS over PaaS?

What are spot instances and when should you use them?

Explain the networking components of IaaS.

IaaS - Infrastructure as a Service

What IaaS Provides

Core IaaS Components

1. Compute (Virtual Machines)

2. Storage

3. Networking

IaaS Providers Comparison

IaaS Use Cases

Real-World Deployment Example

Interview Questions

Continue learning this concept

IaaS - Infrastructure as a Service

What IaaS Provides

Core IaaS Components

1. Compute (Virtual Machines)

2. Storage

3. Networking

IaaS Providers Comparison

IaaS Use Cases

Real-World Deployment Example

Interview Questions

Continue learning this concept