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. If configured so it only
opens
.IR /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)