CERN Accelerator Control Systems to Migrate to Debian 13

Representatives from the European Organization for Nuclear Research (CERN) stated at the MiniDebConf conference that they plan to migrate over 2,200 industrial and embedded computers used to control their accelerator complex from RHEL to Debian 13 by the end of 2026. The systems involved include control computers for the Large Hadron Collider as well as several independent experimental facilities.

CERN also clarified that this migration applies only to accelerator control-related equipment and will not affect data centers or experimental systems. Those data centers and experimental systems will continue to use RHEL/AlmaLinux.

According to reports, CERN engineers had previously considered migrating the relevant systems to CentOS Stream, but ultimately abandoned that approach. The reason is that CentOS Stream is packaged for the x86-64-v2 architecture, using “-march=x86-64-v2”, which includes extension requirements such as SSE3, SSE4_2, SSSE3, POPCNT, LAHF-SAHF, and CMPXCHG16B, making the distribution unable to run on some older hardware.

During the adoption of Debian, CERN also encountered several technical challenges, including the lack of fully functional native tools for automatically building and publishing software packages, the absence of an official policy regarding binary kernel modules, and insufficient support in some tools for handling multiple versions of the same software package within the same repository.

CERN was one of the primary developers of the Scientific Linux distribution. After that distribution was discontinued in 2019, CERN switched to CentOS. In 2022, due to Red Hat's adjustment of CentOS support policies and the early termination of CentOS 8 branch support, CERN adopted AlmaLinux as the standard distribution for its experimental systems, while continuing to use existing CentOS- and RHEL-based systems until the end of their respective lifecycles.