If you follow Linux closely, you won’t be surprised by the news from the Linux Plumbers Conference in Richmond, Virginia — which is the invite-only meeting for top Linux kernel developers — that the recently released Linux 6.6 is the next long-term support version (LTS) of Linux.
Some people had thought the next release might be the not-yet-released Linux 6.7 kernel. After all, the Linux kernel maintainer for the stable branch, Greg Kroah-Hartman, had said that the year’s last kernel will be the LTS version. However, the massive 6.7 update isn’t now expected to see the light of day until some time early next year.
It should be noted that 6.7’s first release candidate only came out on November 12th. And as Linus Torvalds wrote, “This is the biggest merge window we’ve ever had, with 15.4k non-merge commits.”
Linux 6.7 will also include numerous new features, such as the bcachefs file system, which is a new robust copy-on-write (COW) file system that boasts fresh attributes while maintaining high performance. Linux 6.7 will also include support for Nvidia’s GPU System Processor (GSP) firmware in the Nouveau open-source graphics drive and lots of networking updates. It’s a big release in every sense of the word.
In the meantime, Linux 6.6 delivers many good features. These include the KSMBD In-Kernel SMB3 Server, the Earliest Eligible Virtual Deadline First (EEVDF) Scheduler, and support for Intel’s Shadow Stack. You can already find Linux 6.6 powering cutting-edge distros, such as Arch Linux, openSUSE Tumbleweed, and Fedora Linux. By next year, it will be the engine in mainstream distributions, including Canonical‘s next LTS version, Ubuntu 24.04.
As an LTS version, the Linux 6.6 kernel will be supported until December 2026. In the future, there will be fewer LTS Linux kernels. As Jonathan Corbet, Linux kernel developer and executive editor of Linux Weekly News, explained at Open Source Summit Europe, moving forward, Linux kernels LTS is being reduced from six to two years.
Currently, there are six LTS Linux kernels — 6.1, 5.15, 5.10, 5.4, 4.19, and 4.14. Under the process to date, 4.14 would roll off in January 2024, and another kernel would be added. Going forward, though, they won’t be replaced when the 4.14 kernel and the next two drop off.
The explanation for this shift is based on two major factors. First, people aren’t using the older LTS versions. Why spend money and time on projects when they’re sitting idle? The other major reason is that Linux code maintainers are burning out. There’s too much work and not enough hands to handle the load.
Now, if you really want to keep a specific Linux kernel running for a long, long time, you have options. One is to use the Linux Foundation‘s Civil Infrastructure Platform (CIP) super-long-term stable (SLTS) kernel. These kernels power run-time environments for industrial hardware using CIP reference hardware and Debian 11 — and they’re not for general use.
However, if you really want a kernel that you can count on for a decade, Canonical recently reaffirmed its support for the Linux kernels it uses in its LTS Ubuntu releases for 10 years. As Canonical explained: “The Canonical maintenance and support efforts are wholly independent of the upstream LTS and will continue as before. Despite changes in upstream LTS support, Canonical remains committed to providing dependable support for the Ubuntu kernel, ensuring that the Linux community and businesses can continue to rely on stable and secure software.”
So, if you want to commit to using, for example, Ubuntu 20.04 for your computers until early 2030, Canonical will enable you to do that. The company is putting the ‘long’ into long-term support.
Considering the rapid pace of change in computing, though, the mainline Linux kernel’s two-year LTS support window might be what most of you will need and use.