Sometimes your filesystem gets stuck. No operations can be done and a “reboot” will just cause an indefinite waiting time for I/O. There’s a “magical” code that triggers a specific kernel condition - and a reboot.
Watchdog devices are important to be sure our servers are working.
Unfortunately, watchdog daemon seem to crash if enabled on Rasbperry PI.
The problem is that our Pis have a strange watchdog hardware
Sometimes servers can become unresponsive. Both physical and virtual, you may be unable to connect to them, especially when overloaded. So a watchdog can be a solution.