Almalinux vs Rocky Linux: Best CentOS replacement in 2024

If you are looking to replace RHEL with another distribution, there are two that comes to mind. These are Almalinux and Rocky Linux. Both were designed for 1-to-1 compatibility with RHEL. However, which one is the best choice? In this article, let’s look at Almalinux vs Rocky Linux, the differences between the two, and which one you should choose as a RHEL replacement. 

What happened with CentOS?

CentOS Linux was originally an open source Linux OS, community-supported distribution that aimed to be a 1 to 1 functional distro with RHEL, providing a free alternative by rebuilding RHEL’s source code.

However, the direction for CentOS shifted with the introduction of CentOS Stream, which became a rolling release distribution. It now serves as an upstream (development) branch (upstream kernel version) for RHEL. This change was not well-received by users and businesses who relied on CentOS as a stable and predictable OS that was a downstream, production-ready version of RHEL​​.

Rocky Linux

With the change in CentOS AlmaLinux and Rocky Linux emerged as new distributions. Both are open-source and aim to fill the void left by the traditional CentOS, by being binary compatible with RHEL. This compatibility ensures that software designed for RHEL can run seamlessly on these distributions, maintaining the ecosystem’s stability and reliability that users have come to expect.

Rocky Linux was founded by Gregory Kurtzer, who is one of the original creators of CentOS. He wanted to continue the legacy of a stable, free, enterprise-ready operating system that closely aligns with RHEL’s releases. Rocky Linux seeks to maintain 1-to-1 compatibility with RHEL.

Almalinux

AlmaLinux, on the other hand, is developed by CloudLinux, Inc., and aims to provide a community-driven, enterprise-grade Linux distribution that is also binary compatible with RHEL. While AlmaLinux initially pursued a goal similar to Rocky Linux’s, aiming for 1-to-1 compatibility with RHEL, it has slightly adjusted its focus towards being Application Binary Interface (ABI)-compatible, leveraging CentOS Stream’s source code for this purpose​​​​ as we will learn why below.

Both AlmaLinux and Rocky Linux offer long-term support, regular updates, and focus on security and stability, aligning them with enterprise requirements. They support the same architectures as RHEL and include comparable security mechanisms and package managers, making them viable alternatives for enterprise use​​.

RedHat restricts access to source code

But wait what about Red Hat restricting access to source code? Red Hat’s decision to restrict access to RHEL source code means significant adjustments for both AlmaLinux and Rocky Linux.

AlmaLinux has shifted its focus away from striving to be a one-to-one, bug-for-bug compatible clone of RHEL. Instead, AlmaLinux has switched to the aim of maintaining Application Binary Interface (ABI) compatibility with RHEL, planning to leverage CentOS Stream’s source code, which Red Hat continues to make publicly available.

Rocky Linux, on the other hand seems to be confident to be able to continue offering a RHEL-compatible operating system despite the changes. The project acknowledges that Red Hat’s decision impacts the automation used for building Rocky Linux but states that it has already developed short-term mitigation strategies. They are working on a long-term plan to ensure there will be no disruption for Rocky Linux users.

Red Hat’s move has led to much backlash from the open-source community. Many feel it is counter to the spirit of open source and the discussions revolve around the challenges of maintaining compatibility without direct access to RHEL’s source code. This may lead to challenges with downstream distributions being able to innovate and continue their development​​.

Server or Desktop?

You can run Almalinux or Rocky Linux as either a server or desktop. They are both designed to be Enterprise linux distributions that focus on stability, security, and performance that are primarily targeted as a server OS. 

This doesn’t prevent you from using either Almalinux or Rocky Linux as a desktop Linux operating system. Take a look at the Rocky Linux desktop environment pictured below:

Below is a look at Almalinux running as a desktop operating system:

Almalinux vs Rocky Linux: Package management

When comparing AlmaLinux and Rocky Linux, especially in terms of package management, it’s essential to understand that both distributions aim to be as close to Red Hat Enterprise Linux (RHEL) as possible. This means that their package management systems are designed to mirror that of RHEL, ensuring a seamless transition for users moving from RHEL or CentOS. Here’s how package management compares between AlmaLinux and Rocky Linux:

Package Management System

Both AlmaLinux and Rocky Linux utilize the dnf package manager, which is the default package manager for RHEL 8 and later versions. dnf stands for Dandified YUM, which is the next-generation version of YUM (Yellowdog Updater, Modified).

It offers several improvements over YUM, such as better dependency management, faster operation, and support for modular content. This means that both AlmaLinux and Rocky Linux benefit from these improvements, providing a robust and efficient package management experience.

Repositories

Since AlmaLinux and Rocky Linux are binary-compatible with RHEL, they use repositories that closely mirror those available in RHEL. This includes BaseOS for the base operating system packages, AppStream for application streams, and Extras for additional packages not included in RHEL. Both distributions aim to offer a 1:1 compatibility with RHEL, so their repositories are structured to ensure users can find and install packages with the same level of confidence and stability they would expect from RHEL.

Package Availability and Updates

AlmaLinux and Rocky Linux strive to release package updates and security patches with minimal delay from their availability in RHEL. This is crucial for maintaining system security and stability. Both distributions have committed to providing timely updates, leveraging their close alignment with RHEL’s package ecosystem. Users of either distribution can expect regular and reliable updates for their installed packages.

Custom Repositories

Both AlmaLinux and Rocky Linux allow users to configure and use custom repositories, enabling the installation of software packages that may not be available in the official repositories. This flexibility is valuable for users who need to install specific versions of software or access packages provided by third-party repositories.

Management Tools

For package management, both AlmaLinux and Rocky Linux support the same set of command-line tools that come with dnf, such as dnf search for finding packages, dnf install for installing packages, and dnf update for updating the system. The graphical user interface for package management, such as GNOME Software, is also available on both distributions, providing a user-friendly way to manage packages for users who prefer a GUI.

Comparing Almalinux vs Rocky Linux security features

In terms of security, both AlmaLinux and Rocky Linux are designed with robust security features in line with their aim to provide enterprise-grade reliability and compatibility with Red Hat Enterprise Linux (RHEL). However, there are some distinctions in their security approaches and features that might sway users depending on their specific security requirements.

AlmaLinux Security Features:

• AlmaLinux includes the Center for Internet Security (CIS) Benchmark, which is a valuable resource for configuring system security and obtaining comprehensive reports on potential security issues. This feature is particularly useful for organizations looking to adhere to high standards of security compliance and best practices.
• Additionally, AlmaLinux supports the OpenSCAP (Open Security Content Automation Protocol), which automates vulnerability management, measurement, and policy evaluation on systems, further enhancing its security posture.

Rocky Linux Security Features:

• Rocky Linux incorporates security through the use of SELinux (Security Enhanced Linux), a security architecture initially developed by the National Security Agency (NSA). This feature allows administrators greater control over access management on the system, providing an easy way for enforcing security policies.
• Rocky Linux also supports Secure Boot and the Network Time Security protocol for NTP, helping to guarantee the integrity of the boot process and secure time synchronization. These are crucial for system security.

Both distributions are binary compatible with RHEL, ensuring they can run any software or application designed for RHEL without issues. This compatibility extends to their security features, as both distributions inherit the robust security mechanisms of RHEL, including regular security updates and patches.

Choosing Between AlmaLinux and Rocky Linux Based on Security

Choosing between AlmaLinux and Rocky Linux might come down to specific security needs or preferences for security tools and benchmarks. For organizations that prioritize compliance with CIS benchmarks and the use of OpenSCAP for vulnerability management, AlmaLinux may present a slight edge. In contrast, those valuing SELinux’s security architecture and the additional security of Secure Boot might lean towards Rocky Linux.

Ultimately, both distributions offer a secure, enterprise-grade Linux environment with regular updates and a strong community focus, making them both solid choices for replacing CentOS or deploying new Linux-based systems in security-conscious environments.

Development release cycle comparison

Both Rocky Linux and Almalinux are committed to providing stable and secure Linux distributions that are compatible with RHEL, making them both good replacements for CentOS. Their development and release cycles are designed to closely line up with RHEL’s. This helps to make sure users and enterprises have access to a reliable and predictable platform for their infrastructure, much like CentOS used to be.

AlmaLinux Development and Release Cycle

AlmaLinux is managed and released by the AlmaLinux OS Foundation, with CloudLinux Inc. being a significant sponsor. Its development cycle aims to closely follow RHEL’s release cycle, providing users with a free, enterprise-grade operating system that is binary-compatible with RHEL. AlmaLinux releases new major versions shortly after RHEL releases its versions, ensuring users have access to the latest features and security enhancements.

The project commits to regular updates and patches for each release. It also maintains each version for up to 10 years. This long-term support (LTS) model is crucial for enterprise environments needing stability and long-term support for planning and operational continuity.

For more detailed information on AlmaLinux’s development practices and release cycle, visit their official website: AlmaLinux.

Rocky Linux Development and Release Cycle

Rocky Linux is developed by the Rocky Enterprise Software Foundation (RESF) and aims to be a community-driven effort to provide an enterprise-ready operating system that is bug-for-bug compatible with RHEL. Gregory Kurtzer, the founder of CentOS, initiated Rocky Linux with the goal of creating an alternative for those affected by the shift in CentOS’s development model.

Rocky Linux’s release cycle is designed to closely mirror that of RHEL, with efforts to release new versions or security updates shortly after they are available upstream. The project emphasizes quality and reliability, incorporating extensive testing phases before releasing any new version to ensure compatibility and stability.

Rocky Linux also promises long-term support for its releases, aligning with the industry’s expectation for enterprise Linux distributions. This includes regular security updates and patches to ensure systems remain secure and efficient over their lifecycle.

For more information on Rocky Linux’s development process and release strategy, visit their official site: Rocky Linux.

AlmaLinux: Spotlight on Security and Stability

AlmaLinux is known for its “bug for bug compatibility” with RHEL and offers an easy transition for those familiar with the CentOS environment. The latest release, AlmaLinux 9.3 focuses on security enhancements, including the integration of Secure Boot and improvements in Security-Enhanced Linux (SELinux) policies. These enhancements bolster system security, making AlmaLinux an excellent choice for enterprises prioritizing secure, stable, and reliable operating systems for their infrastructure for Linux servers​​.

It also has broad architecture support, including Intel/AMD (x86_64) and ARM64. This ensures versatility across computing environments, from traditional data centers to cloud-native architectures in platforms like Google Cloud. These features and enhancements make AlmaLinux a good choice for enterprise applications that need a robust, secure, and versatile Linux operating system​​​​.

Rocky Linux: Performance and Reliability for Enterprise Workloads

Rocky Linux is a distribution that emphasizes performance, reliability, and a straightforward migration path for CentOS users. Like AlmaLinux, Rocky Linux is developed with a commitment to remaining “bug for bug compatible” with RHEL, ensuring a stable and predictable environment for enterprise applications. The Rocky Linux community and the Rocky Enterprise Software Foundation play important roles in shaping the distribution. It prioritizes features and updates that satisfy the needs of enterprise users and developers.

Rocky Linux also focuses on a stable Linux distribution with comprehensive testing and quality assurance processes. These processes help to ensure each release meets standards for reliability and performance. The distribution’s compatibility with major hardware and software platforms make it a good choice for diverse environments, from on-premise servers to cloud deployments.

Compatibility and Support

Both AlmaLinux and Rocky Linux offer extensive documentation and community support to assist users in migration, configuration, and troubleshooting. With RHEL source code compatibility, both ensure that software packages and environments run as expected on both distributions, with only minor adjustments needed in most cases. This compatibility is important for migrating from CentOS or RHEL with minimal changes and disruptions.

What are others using?

Just taking a quick look at Reddit, it seems like most favored Almalinux over Rocky Linux from what I could see in user feedback. Note the following reasons I picked out from some of the discussions there:

• Alma is a not-for-profit supported by the Cloudlinux organization for funding and has its own board. 
• Some have found the community to be smaller with Alma but friendlier and more helpful
• Alma is quicker with point release, and has a strong community
• Some have seen that Alma is what their VPS’s have had templates for
• Alma supports Docker on Proxmox and Rocky does not
• CERN is using Almalinux

Wrapping up Almalinux vs Rocky Linux

In the “AlmaLinux vs Rocky Linux” debate, the choice comes down to enterprise operating system for your specific needs. Preferences for community engagement, and technical requirements.

These include Secure Boot support and aligning with security benchmarks like the CIS benchmark. Red Hat Enterprise Linux has long been a trusted Linux distro in the enterprise. AlmaLinux and Rocky Linux have both come along as successors for those looking for an alternative to RHEL.

Both distributions are great open-source solutions, offering enterprise-grade stability, security, and reliability. AlmaLinux and Rocky Linux will undoubtedly be the go-to Linux distros that most will use if they need an alternative to CentOS Stream and RHEL.