I need some help understanding FreeBSD's kernel watchdog functionality. I've been reading up, and here's what I think I understand (correct me if I'm wrong):
If a watchdog timer is set in the kernel and not reset or disabled within the time given, the kernel reboots the system. 'watchdog -t <n>' starts a watchdog for n seconds. Runing watchdog(8) again in <n seconds, resets the timer. If 'watchdog -t 0' is run, the kernel disables the watchdog. watchdogd(8) either runs stat(2) on /etc, or a user-defined cmd (with -e), and resets the watchdog only on a zero exit code. There's a few things that aren't clear, though: How many watchdog timers can be enabled at a given time? If more than one, does a single 'watchdog -t 0' disable all timers? Upon timer expiration, can the kernel be configured to do anything OTHER than rebooting? Is it the general idea that watchdog(8) would be run in a script, making sure the script doesn't hang? And that watchdogd(8) is run to ensure the entire system doesn't hang? _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[email protected]"
