CERN is undergoing a major Linux transition that will have more than 2,200 industrial computers and embedded systems across its accelerator infrastructure running Debian 13 “Trixie” by the end of 2026.
The scale is considerable. At MiniDebConf Winterthur 2026, CERN engineers Federico Vaga and Nikos Tsipinakis explained that the accelerator control infrastructure spans roughly 43 square kilometers. It currently includes around 2,200 computers connected to about 17,000 devices, and that number continues to grow.
As you can expect, these are not ordinary office desktops or general-purpose servers. The machines are part of the infrastructure that operates CERN’s accelerator complex, sitting close to the equipment and interfacing with hardware throughout the facilities.
Debian’s announcement confirms the plan to run all 2,200+ industrial and embedded systems on Debian 13 before the end of 2026.
The move is also the latest chapter in CERN’s long Linux history. Its accelerator systems previously followed the Red Hat ecosystem through several generations, moving from Scientific Linux alongside Red Hat Enterprise Linux 5 and 6, and later toward CentOS with the RHEL 7 and 8 generations.
However, CentOS’s change of direction and the premature end-of-life of the traditional CentOS Linux model forced CERN’s accelerator controls team to rethink how closely it wanted to depend on that ecosystem.
Initially, the plan was still to remain there. CERN considered CentOS Stream, with the goal of validating CentOS Stream 9, moving to Stream 10 as soon as possible, and potentially later adopting Stream 11.
At the same time, the team began preparing for the possibility that this approach might not remain viable. One goal was to make CERN’s integration layer distribution-agnostic and prepare a second operating system as a fallback. That fallback was Debian.
What ultimately pushed the decision toward Debian was not simply a preference between Linux distributions. According to the presentation, keeping the existing approach would have created significant hardware and engineering problems.
A risk analysis in the second quarter of 2023 estimated that staying on the Red Hat Enterprise Linux path could require roughly CHF 5.4 million. About 11 hardware boards would need redesigning, more electronic and software engineers and technicians would be required, racks would need reorganizing and rewiring, and most systems would be affected during commissioning.
Even assuming bug-free replacements, CERN estimated an optimistic success rate of only around 20%.
The deadline made the situation more difficult. The accelerator infrastructure had to be ready by the fourth quarter of 2026, leaving little room for an expensive hardware redesign.
Instead, CERN chose what engineers described as a software solution to a software problem: move the accelerator computers to Debian rather than redesign large portions of hardware just to remain compatible with Red Hat Enterprise Linux.
There is another unusual constraint. CERN cannot treat accelerator computers like ordinary servers that can be updated whenever convenient. Accelerator operation follows a carefully planned schedule with operating periods, technical stops, commissioning windows, and long shutdowns.
That means the Linux release under the control infrastructure must fit the accelerator schedule. The team highlighted the need to select the right Debian release to avoid having to “hotpatch a live particle accelerator.”
The migration also goes beyond simply installing Debian onto existing machines. CERN has been redesigning parts of the supporting infrastructure, including the way operating system components are distributed and how front-end computers boot.
Device drivers have also been part of that work. CERN has been rethinking how its specialized hardware drivers integrate with Linux instead of relying too closely on distribution-specific assumptions, an important consideration for machines interfacing with custom accelerator electronics.
So while “2,200 computers moving to Debian” may sound like a fairly conventional Linux migration at first glance, the environment makes this one rather different. These systems are spread across CERN’s accelerator facilities, connect to tens of thousands of devices, and operate in an infrastructure where downtime, hardware compatibility, and long-term lifecycle planning have direct operational consequences.
So, by the end of this year, Debian 13 should have a particularly interesting deployment to add to its resume: running the industrial and embedded computing layer behind CERN’s accelerator control infrastructure.
For additional details, watch the talk on the topic given at the Winterthur MiniDebConf.
