Differences Between CentOS 7 and AlmaLinux 9.x: What to Expect After Switching

CentOS has long been a trusted choice for enterprise and server environments. However, with the shift in CentOS development to CentOS Stream, many users have migrated to alternatives like AlmaLinux. AlmaLinux 9.x, developed as a direct replacement for CentOS, offers a stable and secure platform for businesses. This blog explores the key differences between CentOS 7 and AlmaLinux 9.x and highlights the benefits clients can enjoy after making the switch.

Key Differences Between CentOS 7 and AlmaLinux 9.x

1. Release Model

• CentOS 7:

  • Follows a traditional release model, with updates and support for a specific lifecycle.

  • End-of-Life (EOL) for CentOS 7 is June 30, 2024.

• AlmaLinux 9.x:

  • Follows Red Hat Enterprise Linux (RHEL) closely, offering binary compatibility.

  • Supported with long-term updates and security patches.

2. Kernel Version

• CentOS 7:

  • Ships with an older 3.10 kernel, which limits hardware compatibility and performance for modern systems.

• AlmaLinux 9.x:

  • Uses the newer 5.14 kernel, offering improved hardware support, enhanced performance, and better power efficiency.

3. Default Software Packages

• CentOS 7:

  • Features older versions of software packages, including outdated Python, Apache, and PHP versions.

• AlmaLinux 9.x:

  • Provides updated software stacks, including:

    • Python 3.9.

    • PHP 8.0.

    • Apache 2.4 with newer features and performance enhancements.

4. Security Enhancements

• CentOS 7:

  • Lacks support for many modern security protocols and frameworks.

• AlmaLinux 9.x:

  • Includes significant security improvements:

    • SELinux enhancements for better policy management.

    • OpenSSL 3.0 for improved cryptographic performance and security.

    • Updated firewalld for managing complex firewall rules.

5. Container Support

• CentOS 7:

  • Basic support for container technologies, but limited to older versions of Docker.

• AlmaLinux 9.x:

  • Enhanced support for containerization with:

    • Podman and Buildah as Docker alternatives.

    • Seamless integration with Kubernetes.

6. Performance and Efficiency

• CentOS 7:

  • Designed for older systems, resulting in suboptimal performance on modern hardware.

• AlmaLinux 9.x:

  • Optimized for modern CPUs and storage devices, improving performance and scalability.

Benefits of Switching to AlmaLinux 9.x

1. Long-Term Support

Clients migrating to AlmaLinux 9.x gain access to a robust support lifecycle, with updates and security patches for at least 10 years.

2. Improved Security

• Enhanced security features reduce vulnerabilities and protect critical infrastructure.

• Faster updates ensure immediate fixes for discovered vulnerabilities.

3. Access to Modern Software

• AlmaLinux provides updated versions of essential software, supporting modern development and hosting needs.

• Compatible with DevOps tools and workflows, including CI/CD pipelines.

4. Seamless Migration Tools

• AlmaLinux offers a free migration script to help users transition from CentOS 7 without significant downtime or data loss.

5. Community-Driven Development

• Supported by a global community and governed by a non-profit foundation, ensuring transparency and open development.

6. Containerization Support

• Native support for Podman, Kubernetes, and other container technologies makes AlmaLinux ideal for deploying cloud-native applications.

How to Migrate from CentOS 7 to AlmaLinux 9.x

Step 1: Backup Your Data

Before migration, ensure all critical data and configurations are backed up.

Step 2: Download the AlmaLinux Migration Tool

Install the official migration script provided by AlmaLinux:

				
					curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh
				
			

Step 3: Run the Migration Script

Execute the migration script to start the process:

				
					bash almalinux-deploy.sh
				
			

Step 4: Verify Migration

After the script completes, verify the migration:

				
					cat /etc/redhat-release
				
			

You should see “AlmaLinux 9.x” as the output.

Step 5: Reboot and Test

Reboot the server and test all services to ensure they function as expected.

Conclusion

Switching from CentOS 7 to AlmaLinux 9.x is a forward-looking decision for businesses and developers. AlmaLinux offers enhanced security, modern software support, and robust performance tailored for current and future demands. With its seamless migration process and long-term support, AlmaLinux is an excellent choice for those seeking stability and reliability in their Linux environments.