Release 2025_021 (2025-06-30)

Impact

24.11

  • the following services will be restarted: redis.service, mysql.service, opensearch.service, postgresql.service

  • Machines will reboot to activate the changed kernel.

NixOS 24.11 platform

  • Linux kernel: use 6.12.x LTS series as default stable kernel (PL-133760)

    Promote the 6.12.x LTS Linux kernel series as our default stable kernel.

    This seems to help resolve some recent IO latency / stalling issues

  • Memory management: switch to smaller, fixed size dirty page buffers (PL-133760)

    This also seems to be a factor in the recent IO latency / stalling issues: The dirty page buffers were based on percentages of the installed RAM so far, but can cause long periods of stalling when the kernel passes the hard threshold to flush it.

    We now provide much smaller and fixed sizes for dirty pages (16 MiB to start flushing in the background and 64 MiB to enforce flushing).

  • agent: the command fc-manage switch now has a -R option which will activate the new configuration by performing an immediate reboot, similar to the process used for upgrading between major versions. (PL-133308)

  • Pull upstream NixOS changes, security fixes, and package updates:

    • chromedriver: 137.0.7151.103 -> 137.0.7151.119

    • chromium: 137.0.7151.103 -> 137.0.7151.119

    • linuxKernelStable: 6.6.93 -> 6.6.94

    • linuxKernelVerify: 6.12.33 -> 6.12.34

    • matrix-synapse: 1.131.0 -> 1.132.0

    • sudo: 1.9.16p2 -> 1.9.17

    • tomcat10: 10.1.41 -> 10.1.42

    • tomcat9: 9.0.105 -> 9.0.106

    • nix: fix GHSA-g948-229j-48j3

Detailed Changes