NAME
wd_keepalive - a simplified software watchdog daemon
SYNOPSIS
wd_keepalive [-c filename|--config-file filename]
DESCRIPTION
This is a simplified version of the watchdog daemon. It only opens
/dev/watchdog, and keeps writing to it often enough to keep the kernel
from resetting, at least once per minute. Each write delays the reboot
time another minute. After a minute of inactivity the watchdog hardware
will cause a reset. In the case of the software watchdog the ability to
reboot will depend on the state of the machines and interrupts.
The wd_keepalive daemon can be stopped without causing a reboot if the
device /dev/watchdog is closed correctly, unless your kernel is
compiled with the CONFIG_WATCHDOG_NOWAYOUT option enabled.
Under high system load wd_keepalive might be swapped out of memory and
may fail to make it back in in time. Under these circumstances the
Linux kernel will reset the machine. To make sure you won’t get
unnecessary reboots make sure you have the variable realtime set to yes
in the configuration file watchdog.conf. This adds real time support
to wd_keepalive: it will lock itself into memory and there should be
no problem even under the highest of loads.
On system running out of memory the kernel will try to free enough
memory by killing process. The wd_keepalive daemon itself is exempted
from this so-called out-of-memory killer.
OPTIONS
Available command line options are the following:
-c config-file, --config-file config-file
Use config-file as the configuration file instead of the default
/etc/watchdog.conf.
FILES
/dev/watchdog
The watchdog device.
/var/run/wd_keepalive.pid
The pid file of the running wd_keepalive.
SEE ALSO
watchdog.conf(5)
watchdog(8)