De acordo com o homem watchdog.conf:
interval = <interval>
Set the highest possible interval between two writes to the watchdog device.
Default value is 1 second. The kernel drivers expects a write command every minute. Otherwise the system will be rebooted.
Therefore an interval of more than a minute can only be used with the -f command-line option.
Como definir o que 'os drivers do kernel esperam'? O que a opção de linha de comando '-f' deve fazer?