Rocky Linux vs. AlmaLinux: Differences & Which is better?

The discontinuation of CentOS Linux in December 2020 left many organizations relying on CentOS without a stable, long-term support system. To address this, two new Linux distributions were created: AlmaLinux and Rocky Linux. Both distributions are based on Red Hat Enterprise Linux (RHEL) and offer a free, enterprise-grade alternative.

This article will explore the AlmaLinux vs. Rocky Linux comparison, including their origins, lifecycle and support duration, enterprise features, and more.

AlmaLinux vs Rocky Linux: Key Takeaways

Both AlmaLinux and Rocky Linux were born out of the need for a community-maintained RHEL-based distribution after the announcement that CentOS Linux would no longer be positioned as a direct competitor to RHEL.

The table below highlights the key differences:

AlmaLinux vs. Rocky Linux: Key Differences

Origins and Community Governance

AlmaLinux was developed by CloudLinux shortly after Red Hat’s announcement to discontinue CentOS Linux in favor of CentOS Stream. AlmaLinux has since evolved into a vibrant community-driven project with the AlmaLinux OS Foundation governing its development.

Following the restriction of public access to RHEL source code, AlmaLinux strategically shifted its focus from strict 1:1 RHEL compatibility to Application Binary Interface (ABI) compatibility. This approach provides greater flexibility while ensuring that applications built for RHEL run seamlessly on AlmaLinux without modifications.

Rocky Linux, on the other hand, remains committed to its mission of being a 1:1 drop-in replacement for RHEL. It also aims to be a community-driven, RHEL-compatible distribution. This task is made more difficult with each change made by Red Hat to it’s source code access, forcing Rocky to obtain said source code through various other avenues. It remains vulnerable to potential disruption caused by further restrictions to Red Hat’s licensing or source availability.

Release Cycle and Stability

Both AlmaLinux and Rocky Linux follow RHEL’s release cycle, ensuring compatibility and timely updates. When RHEL releases a new version, both distributions work rapidly to rebuild and release their versions. However, notable differences in timing and efficiency exist.

AlmaLinux consistently demonstrates faster release times for updates, patches, and security fixes. Its efficient build and distribution pipeline is community controlled, having evolved from proven infrastructure already in place at CloudLinux. This translates to quicker access to critical security patches for users, including backporting fixes not yet picked up by Red Hat directly from upstream projects.

Rocky Linux has a reliable release cycle, though it typically lags behind AlmaLinux by several days when delivering updates. (Source: OpenLogic)

Enterprise Adoption and Use Cases

Both AlmaLinux and Rocky Linux are increasingly being adopted by enterprises seeking a reliable CentOS replacement. However, certain enterprises may prefer one over the other based on their specific needs.

AlmaLinux has seen broad adoption in cloud environments and organizations that value corporate-backed support options. It’s particularly popular in environments where quick updates and security patches are critical to maintaining operations. Its early release after CentOS’s shift helped AlmaLinux capture a significant portion of users transitioning from CentOS. Additionally, AlmaLinux offers builds for diverse platforms including Raspberry Pi, WSL, container images, and vagrant boxes, making it suitable for a wider range of use cases.

Rocky Linux’s initial growth was fueled mostly by the name associated with previous CentOS development. A more attentive look at the history of the CentOS project and its later corporate “takeover” and eventual shutdown does seem to hint at a need for better reasons for choosing it over alternatives, lest history repeat itself (or rhymes).

Similarities Between AlmaLinux and Rocky Linux

Despite their differences, AlmaLinux and Rocky Linux share several key characteristics that make them viable alternatives to RHEL and successors to CentOS:

RHEL Compatibility

Both distributions are designed to maintain compatibility with RHEL, ensuring that organizations running applications on CentOS or RHEL can migrate seamlessly to either distribution without modifying their workflows.

Package Management

Both AlmaLinux and Rocky Linux utilize the Red Hat Package Manager (rpm) and the Dandified Yum (DNF) package manager. This ensures compatibility with RPM-based software packages, allowing users to continue leveraging the same tools, repositories, and updates as they did with CentOS.

Long-Term Support and Lifecycle

Both distributions offer long-term support with a lifecycle of approximately 10 years, mirroring RHEL’s support timeline. AlmaLinux offers long-term support for its releases, with AlmaLinux 8 supported until 2029 and AlmaLinux 9 until 2032. Similarly, Rocky Linux provides long-term support and bug fixes, with version 8 supported through 2029 and version 9 until 2032. This makes both distributions a dependable choice for enterprises looking for stability and extended security updates.

For enterprises seeking a comprehensive and reliable support solution for AlmaLinux, TuxCare offers Enterprise Support for AlmaLinux. With a 16-year support lifecycle, a commercial repository, and extended security updates, TuxCare provides peace of mind and ensures uninterrupted operations. Additionally, their break-and-fix support and affordable pay-as-you-go application support make it a compelling choice for businesses of all sizes.

Security Features

Both AlmaLinux and Rocky Linux prioritize security and provide robust features to protect enterprise systems. These features include:

SELinux: Both distributions enable SELinux by default, a mandatory access control security kernel module that helps prevent unauthorized access to system resources.

Secure Boot: Both support Secure Boot, a security feature that verifies the authenticity of software during the boot process, helping to prevent unauthorized access and malware. AlmaLinux has offered Secure Boot since the 8.4 release, Rocky followed with support starting with version 8.5.

Vulnerability Management and Patching: Both distributions receive regular security updates to address known vulnerabilities. AlmaLinux has historically released new versions faster, following Red Hat’s releases by a couple of days.

System Hardening: Implementing Linux system hardening techniques, such as disabling unnecessary services, enforcing strong authentication policies, and configuring firewall rules, further strengthens AlmaLinux and Rocky Linux against cyber threats. These measures help enterprises reduce attack surfaces and enhance overall system security.

It’s worth noting that AlmaLinux Foundation works with existing Special Interest Groups (SIGs), empowering existing communities rather than creating new ones, thus avoiding divisions when shared security interests exist.

Rocky Linux and AlmaLinux: More Use Cases

Rocky Linux and AlmaLinux are great CentOS replacements, but they are much more than that. With their long-term support, enterprise-grade security, and rock-solid stability, they are a good fit for everything from cloud platforms to high-performance computing. Let’s look at three key use cases.

1. Mission-Critical Systems

Both distributions offer the kind of stability, security patches, and support needed for mission-critical environments, like data centers, financial institutions, and government agencies.

2. Cloud and Virtualization

Rocky Linux and AlmaLinux are optimized for cloud environments and have official images available on AWS, Azure, and Google Cloud. They support containerized workloads, hybrid cloud setups, and virtualization tools like KVM, VMware, and OpenStack. It’s worth noting that Microsoft recently endorsed AlmaLinux as an officially supported distribution on Azure. AlmaLinux’s extensive platform support, including container images and vagrant boxes, makes it particularly versatile for various deployment scenarios.

3. High-Performance Computing (HPC)

HPC, AI, and machine learning applications demand performance and stability — and Rocky Linux and AlmaLinux are built for this kind of workload. They both support parallel computing, the RHEL-based HPC tools that researchers rely on, and even supercomputing workloads. AlmaLinux’s support for Raspberry Pi provides additional flexibility for edge computing and IoT projects that complement HPC environments.

Rocky Linux vs. AlmaLinux: Which One Should You Choose?

Choosing between Rocky Linux and AlmaLinux is a tough choice because both are really good. The right choice depends on your use case and specific needs. Since both can run any workload that runs on Red Hat Linux, this is not really a discriminating factor for either.

AlmaLinux, on the other hand, offers a bit more flexibility. With CloudLinux backing, it’s also a popular choice for web hosting providers, managed service providers (MSPs), and businesses that prefer a slightly more adaptable approach. It is well suited for organizations that want enterprise-grade support without strict adherence to upstream RHEL. 

If security and confidentiality are a core concern, you can get FIPS validated AlmaLinux, with extensive support provided by TuxCare’s AlmaLinux Support.

Both distributions provide long-term support and security updates, so the best choice depends on what aligns better with your needs.

How to Migrate from CentOS to AlmaLinux or Rocky Linux

Migrating from CentOS to AlmaLinux or Rocky Linux is generally straightforward, thanks to dedicated migration tools. Before starting any migration, it is absolutely essential to create a full backup of your CentOS system. This ensures safety of your data in case unforeseen issues appear during the migration process.

Migrating to AlmaLinux

AlmaLinux provides the Leapp utility (part of the ELevate project) for in-place upgrades. This powerful tool not only supports migrations to AlmaLinux but also between various distributions including CentOS Stream, Rocky Linux, and Oracle Linux, demonstrating AlmaLinux’s commitment to flexibility and cooperation. The Leapp tool performs one-step upgrades, so migrating from CentOS 7 to AlmaLinux 9 requires a two-stage process:

• CentOS 7 to AlmaLinux 8
• AlmaLinux 8 to AlmaLinux 9

We’ve also created a detailed tutorial to walk you through the CentOS 8 to AlmaLinux 9 migration process step by step.

Migrating to Rocky Linux

Rocky Linux offers the migrate2rocky.sh script for migration.

• Download the script:

curl https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh -o migrate2rocky.sh

• Make it executable and run it:

chmod u+x migrate2rocky.sh

sudo ./migrate2rocky.sh -r

The -r option performs the migration.

• Reboot and verify:

After it shows the “Complete!” message, reboot the system.

sudo reboot

Verify the migration by checking the OS release.

cat /etc/os-release

Final Thoughts

Both AlmaLinux and Rocky Linux have emerged as strong contenders to replace CentOS in enterprise environments. While both offer RHEL compatibility and long support windows, AlmaLinux stands out with its faster update cycle, broader platform support, and collaborative approach to the Linux ecosystem.

AlmaLinux’s flexibility, combined with its support for diverse platforms including Raspberry Pi, WSL, container images, and vagrant boxes, makes it the more versatile choice for a wider range of use cases. The ELevate tool’s ability to facilitate migrations between various distributions further highlights AlmaLinux’s commitment to cooperation rather than division in the Linux community.

For further enhancing system security and uptime, consider implementing rebootless patching, also known as “live patching,” as part of your security strategy. Live patching allows you to apply security updates to a running kernel without requiring a reboot.

TuxCare’s KernelCare Enterprise offers automated rebootless patching for all popular enterprise distributions, including AlmaLinux, Rocky Linux, RHEL, CentOS, Ubuntu, Debian, Oracle Linux, CloudLinux, and more. KernelCare ensures continuous operations while safeguarding against critical vulnerabilities, eliminating the need for system reboots after kernel updates.

Want to know more about KernelCare live patching? Ask our security experts today.

Summary

Article Name

AlmaLinux and Rocky Linux: Comparing Enterprise Linux Distros

Description

Compare AlmaLinux and Rocky Linux, two popular RHEL-based Linux distributions. Learn key differences to choose the right CentOS replacement.

Author

Rohan Timalsina

Publisher Name

TuxCare

Publisher Logo