Amazon Linux AMI is AWS's custom-built operating system optimized for EC2. While AWS doesn't officially declare its base distribution, package managers and system internals reveal its relationship with Red Hat Enterprise Linux (RHEL). The Amazon Linux team maintains close compatibility with RHEL while adding AWS-specific optimizations.

Several technical markers confirm the RHEL lineage:

• Package management using yum (in Amazon Linux 1/2) and dnf (in Amazon Linux 2022)
• System initialization via systemd
• Similar directory structure (/etc/sysconfig patterns)
• RPM package format

Here's how different Amazon Linux versions map to RHEL:

# Check release information (works on all Amazon Linux versions)
cat /etc/os-release

# Sample output for Amazon Linux 2:
NAME="Amazon Linux"
VERSION="2"
ID="amzn"
ID_LIKE="centos rhel fedora"

Understanding this relationship helps when:

• Porting RHEL/CentOS applications to AWS
• Troubleshooting compatibility issues
• Following RHEL security advisories

For example, when installing development tools:

# Python development setup (similar to RHEL)
sudo yum groupinstall "Development Tools"
sudo yum install python3-devel

The RHEL base becomes crucial in these scenarios:

# Kernel module development
# Requires RHEL-compatible kernel headers
sudo yum install kernel-devel-$(uname -r)

Or when dealing with SELinux policies:

# Check SELinux status (RHEL-style command)
sestatus

While based on RHEL, Amazon Linux includes AWS-specific modifications:

• Different release cadence
• Pre-configured AWS tools (awscli, EC2 utils)
• Alternative package repositories
• Optimized kernel parameters for EC2

As an AWS-focused developer, understanding the foundation of Amazon Linux AMI is crucial for package compatibility and system administration. The current generation (Amazon Linux 2023) maintains its heritage as a RHEL/CentOS derivative, though with significant AWS-specific optimizations.

The most telling indicator is Amazon Linux's use of yum (and now dnf in AL2023) package management, identical to RHEL's ecosystem:

# Check base repos configuration
cat /etc/yum.repos.d/amzn2-core.repo

# Compare with CentOS stream:
cat /etc/yum.repos.d/CentOS-Stream-AppStream.repo

Amazon Linux tracks closely with RHEL's kernel versions and systemd implementations. This becomes evident when checking running services:

# Kernel version check shows RHEL-compatible build
uname -r
4.14.252-195.483.amzn2.x86_64

# Systemd unit file structure matches RHEL
ls -l /usr/lib/systemd/system/

• Enhanced AWS tooling: Includes optimized ENA drivers, EC2 utils pre-installed
• Security updates: Patches often arrive before RHEL equivalents
• Package variations: Some RHEL packages replaced with Amazon alternatives (e.g., different Java implementations)

Converting RHEL-specific automation scripts to Amazon Linux typically requires minimal changes. Here's an Ansible snippet that works on both:

- name: Install common packages
  yum:
    name:
      - httpd
      - amazon-efs-utils
      - aws-cli
    state: present

While Amazon Linux covers most use cases, you might need standard RHEL for:

1. Strict regulatory compliance requiring Red Hat certification
2. Specialized hardware drivers only available in RHEL
3. Enterprise support contracts with Red Hat

The Amazon Linux release cadence mirrors RHEL's major version lifecycle. Compare:

# Check Amazon Linux release cycle
cat /etc/system-release

# Versus RHEL equivalent
cat /etc/redhat-release

The version numbering and support timelines show clear alignment.