I’m experiencing random lockups of one of my nodes. It’s a Pi4 running HAOS 14.1 and 2024.12.5. Looking at the backend journal, it just stops. The watchdog doesn’t bite and reboot the Pi as it should after this commit Enable watchdog control in systemd by sbyx · Pull Request #2628 · home-assistant/operating-system · GitHub
The watchdog is configured in /usr/lib/systemd/system.conf.d/watchdog.conf
which contains:
[Manager]
RuntimeWatchdogSec=default
WatchdogDevice=/dev/watchdog
Running systemctl show | grep watchdog
gets
WatchdogDevice=/dev/watchdog0
but nothing about the timeout. The help: systemd-system.conf shows that RuntimeWatchdogSec
needs to be non-zero for the watchdog to be enabled and that its default is defined at compilation time of the kernel.
So, what default is configured in the kernel? And why is the watchdog not biting?