Linux Kernel Life Cycle Explained

Introduction

The Linux kernel, the core of the Linux operating system, is a complex piece of software that is constantly evolving. Understanding its life cycle is crucial for anyone involved in the Linux ecosystem, from developers and maintainers to system administrators and end users.

Prepatch (or “RC”) Phase

The life cycle of a new Linux kernel version begins with the prepatch phase, also known as the -rc (release candidate) phase. During this phase, new features and changes are introduced into the kernel source tree by the kernel maintainers. These changes are tested, bugs are fixed, and the kernel stabilizes.

Mainline Phase

Once the kernel maintainers decide that the kernel is stable enough, the version is released as a mainline kernel. This is the version of the kernel where new features are considered stable, but it’s not yet recommended for production use. It’s at this point that Linux distributions may start to integrate the new kernel into their testing releases.

Stable Review Phase

After the mainline kernel is released, it enters the stable review phase. During this phase, the kernel undergoes extensive testing and bug fixing. Only critical fixes are allowed into these kernels, and they’re released as point releases (e.g., 5.8.1, 5.8.2, etc.).

Long-Term Support (LTS) Phase

Some kernel versions are designated as Long-Term Support (LTS) kernels. These kernels are maintained for a longer period, typically for two years, and receive backports of critical fixes and hardware support from newer mainline kernels.

End of Life (EOL)

Eventually, every kernel version reaches its End of Life (EOL). This means that no more updates or fixes, not even for critical security issues, will be released for this version. At this point, users are strongly encouraged to upgrade to a newer kernel version.

Conclusion

Understanding the life cycle of the Linux kernel is essential for making informed decisions about which kernel version to use, when to upgrade, and what level of support you can expect. Whether you’re a developer, a system administrator, or an end user, keeping track of the kernel’s life cycle can help you ensure that your systems are secure, stable, and up-to-date.

Disclaimer

This article is intended for educational purposes only and does not constitute professional advice. The information provided is based on the best of our knowledge and we do not guarantee its accuracy or completeness. Always conduct your own research and consult with a professional before making any decisions based on this information.