CERN Moves Accelerator Control Systems to Debian

CERN Transitioning To Debian After Being A Longtime RHEL Institution – Phoronix https://share.google/CJ8nF8mogzr2NN2IL

In September 2026, Phoronix reported that CERN, the European Organization for Nuclear Research, is moving its industrial accelerator-control computers to Debian. CERN has long been a Red Hat shop, so the news surprised a lot of Linux users.

Background

CERN co-maintained Scientific Linux, a RHEL rebuild, with other research institutions. It used Scientific Linux for about a decade and then moved to CentOS in 2015. After roughly ten more years on CentOS, part of its fleet is now leaving the RHEL family. CERN presented the plan at the MiniDebConf in Winterthur, Switzerland.

Why Debian?

CERN engineers looked at CentOS Stream as the natural next step. What finally ruled it out was the -march=x86-64-v2 compiler baseline, which they called “the straw that broke the camel’s back.” Newer RHEL releases are built for the x86-64-v2 level (and RHEL 10 for x86-64-v3), so older CPUs without those instructions can’t run them. CERN calls that “forced obsolescence.” Accelerator-control systems often run on long-lived industrial hardware, which made it a dealbreaker. Debian still supports the baseline x86-64 level.

Not a full exit from RHEL

Phoronix later added an update from CERN. The move covers the industrial accelerator-control computers only. Data centres and experiment computing stay on RHEL and AlmaLinux. CERN plans to have all of its more than 2,200 industrial computers and embedded systems on Debian 13 by the end of 2026.

Problems they hit

CERN described a few gaps in Debian’s tooling. There is no standard way to build and publish packages automatically for a site, and several tools can’t handle more than one version of the same package. Anyone moving an RPM-based fleet to Debian will probably run into the same things.

Why it matters to sysadmins

Check your CPU baseline before you upgrade. Run /lib64/ld-linux-x86-64.so.2 --help | grep supported on glibc 2.33 or newer to see which x86-64 levels a machine supports, before you plan a jump to a newer EL release.
Mixed fleets are normal. CERN’s split is common: RHEL or AlmaLinux in the data centre and something else on embedded or legacy hardware.
Plan for packaging. Moving from yum/dnf to apt means changes to internal repositories, configuration management and image pipelines.

Source

Original link: https://share.google/CJ8nF8mogzr2NN2IL, which points to Phoronix: CERN Transitioning Industrial Computers To Debian.

CERN Moves Accelerator-Control Computers to Debian After Years on RHEL