RHEL Alternatives: AlmaLinux vs Rocky Linux vs Oracle Linux vs CentOS Stream

Introduction

The discontinuation of CentOS Linux in 2020 sent shockwaves through the Linux community, leaving many organizations scrambling to find a suitable replacement for their mission-critical workloads. While the decision was unexpected, it has since sparked the emergence of several promising alternatives that aim to fill the void left by CentOS.

In this comprehensive guide, we’ll explore the key players in the post-CentOS landscape, including Red Hat Enterprise Linux (RHEL), Oracle Linux, AlmaLinux, Rocky Linux, and CentOS Stream. We’ll dive into the unique features, strengths, and considerations of each distribution, helping you make an informed decision on the best fit for your organization’s needs.

Red Hat Enterprise Linux (RHEL)

As the original source of CentOS, Red Hat Enterprise Linux (RHEL) is a natural choice for organizations seeking a reliable and enterprise-grade Linux distribution. RHEL is a commercial offering from Red Hat, a leading contributor to the Linux kernel and a trusted name in the open-source community.

Key Features:

• Robust security features, including customizable cryptography policies, built-in authentication tools, and regular vulnerability scans
• Support for a wide range of architectures, including x86_64, ARM64, IBM Z, IBM LinuxONE, and IBM Power
• Comprehensive container development tools, native deployment tools, and multiple security layers
• Access to Red Hat’s extensive software management, automation, middleware, and visualization tools

Considerations:

• RHEL requires a paid subscription, starting at $349 per year, which may not be feasible for all organizations, especially smaller ones or those with limited budgets.
• The subscription-based model may be a barrier for some users who are accustomed to the free and open-source nature of CentOS.

AlmaLinux

AlmaLinux is a community-driven, enterprise-grade Linux distribution that was created to fill the void left by CentOS. Backed by CloudLinux, AlmaLinux aims to provide a production-ready, binary-compatible alternative to RHEL.

Key Features:

• Binary compatibility with RHEL, allowing for a seamless migration from CentOS
• A robust community-driven development process, with contributions from a wide range of developers and users
• Availability of a conversion script called “migrate2alma” to help CentOS users transition to AlmaLinux
• Long-term support, with a 10-year lifecycle for each major release

Considerations:

• While AlmaLinux has gained significant traction in the Linux community, it is a relatively new distribution, and some organizations may prefer a more established option.
• The reliance on the CloudLinux company for sponsorship and support may be a concern for some users who prefer a fully community-driven project.

Rocky Linux

Rocky Linux is another community-driven RHEL-compatible distribution that was created by Gregory Kurtzer, one of the original founders of the CentOS project. Rocky Linux aims to provide a production-ready, binary-compatible alternative to RHEL.

Key Features:

• Binary compatibility with RHEL, allowing for a seamless migration from CentOS
• A community-driven development process, with contributions from a wide range of developers and users
• Availability of a conversion script called “migrate2rocky” to help CentOS users transition to Rocky Linux
• Long-term support, with a 10-year lifecycle for each major release

Considerations:

• As a relatively new distribution, Rocky Linux may not have the same level of community support and ecosystem as more established options like RHEL or Ubuntu.
• The reliance on the community for sponsorship and support may be a concern for some organizations that prefer a commercially-backed distribution.

Oracle Linux

Oracle Linux is another RHEL-compatible distribution that has emerged as a potential replacement for CentOS. Developed and maintained by Oracle, this distribution aims to provide a reliable and enterprise-ready Linux platform.

Key Features:

• Binary compatibility with RHEL, allowing for a seamless migration from CentOS
• Availability of the Unbreakable Enterprise Kernel (UEK), which provides additional stability and performance enhancements
• Integration with Oracle’s Ksplice technology, enabling live kernel patching without the need for reboots
• Access to Oracle’s extensive software portfolio and support services

Considerations:

• Some users may be hesitant to adopt a distribution closely tied to a commercial entity like Oracle, preferring a more community-driven approach.

CentOS Stream

CentOS Stream is a unique distribution in the post-CentOS landscape, as it serves as the upstream development branch for RHEL. Unlike the previous CentOS Linux, which was a downstream rebuild of RHEL, CentOS Stream is a more actively developed distribution that provides a glimpse into the future of RHEL.

Key Features:

• Serves as the upstream development branch for RHEL, allowing users to stay on the cutting edge of Red Hat’s Linux development
• Provides a more frequent release cycle compared to traditional RHEL, with updates and new features being introduced more rapidly
• Offers a testing ground for new technologies and features before they are incorporated into the stable RHEL releases

Considerations:

• CentOS Stream is primarily intended for developers and early adopters, as it may not offer the same level of stability and predictability as traditional RHEL or other CentOS alternatives.
• The more frequent release cycle and focus on new features may not be suitable for organizations that require a more conservative and stable operating system for their mission-critical workloads.

Comparing the Alternatives

When choosing a CentOS replacement, it’s important to consider factors such as your organization’s specific needs, budget, and long-term goals. To help you make an informed decision, let’s compare the key aspects of the distributions we’ve discussed:

Compatibility with RHEL

• RHEL, Oracle Linux, AlmaLinux, and Rocky Linux are all binary-compatible with RHEL, making them the most straightforward replacements for CentOS.
• CentOS Stream, while related to RHEL, is not a direct binary-compatible replacement, as it serves as the upstream development branch.

Community and Sponsorship

• RHEL is a commercial offering from Red Hat, a leading contributor to the Linux kernel and open-source community.
• AlmaLinux and Rocky Linux are community-driven projects, with sponsorship from CloudLinux and the community, respectively.
• Oracle Linux is sponsored and maintained by Oracle, a commercial entity.
• CentOS Stream is sponsored and maintained by Red Hat as the upstream development branch for RHEL.

Popularity and Adoption

• RHEL is a well-established and widely adopted enterprise Linux distribution.
• Oracle Linux, AlmaLinux, and Rocky Linux are relatively new distributions, but have been gaining traction in the Linux community.
• CentOS Stream adoption is more limited compared to the other options.

Release Cycle and Support

• RHEL, AlmaLinux, Rocky Linux, and Oracle Linux typically have longer support lifecycles, with up to 10 years of updates and security patches for major releases.
• CentOS Stream has a more frequent release cycle, with updates and new features being introduced more rapidly than traditional RHEL releases.

Pricing and Commercial Support

• RHEL requires a paid subscription, starting at $349 per year, which may not be feasible for all organizations.
• AlmaLinux and Rocky Linux are free and open-source, with community-driven support.
• CentOS Stream is free to use, but may not offer the same level of commercial support as RHEL or Oracle Linux.
• Oracle Linux offers a free download, but organizations may need to purchase a support subscription for certain premium features.

Choosing the Right CentOS Replacement

When selecting a CentOS replacement, it’s essential to carefully evaluate your organization’s specific needs and requirements. Consider factors such as compatibility with your existing infrastructure, the level of commercial support you require, your budget, and the long-term stability and predictability of the distribution.

For organizations that require a well-established, enterprise-grade Linux distribution with commercial support, RHEL or Oracle Linux may be the best fit. These distributions offer the highest level of binary compatibility with CentOS, as well as extensive support and security features.

If your organization prioritizes a community-driven approach and a more cost-effective solution, AlmaLinux or Rocky Linux may be the better choice. These distributions aim to provide a production-ready, RHEL-compatible alternative, with the added benefit of a 10-year support lifecycle for each major release.

CentOS Stream may be a suitable option for organizations that are willing to embrace a more frequent release cycle and a more actively developed distribution, particularly if they have a strong in-house Linux expertise to manage the potential instability and changes.

The decision on which CentOS replacement to choose will depend on your organization’s specific needs, budget, and long-term goals. By carefully evaluating the features, strengths, and considerations of each distribution, you can make an informed decision that will best serve your organization’s requirements.

Conclusion

The discontinuation of CentOS Linux has undoubtedly created a void in the Linux ecosystem, but the emergence of several promising alternatives has provided organizations with a range of options to choose from. Whether you opt for the enterprise-grade RHEL, the community-driven AlmaLinux or Rocky Linux, or the more actively developed CentOS Stream, there is a CentOS replacement that can meet your organization’s needs.

By thoroughly understanding the key features, strengths, and considerations of each distribution, you can make an informed decision that will ensure the long-term stability, security, and success of your mission-critical workloads. As the Linux landscape continues to evolve, staying informed and adaptable will be crucial for organizations navigating the post-CentOS era.