Quite often times when I do a reboot, I get the following error message:
kernel: watchdog watchdog0: watchdog did not stop!
I tried to find out more about watchdog by doing man watchdog
, but it says no manual entry. I tried yum list watchdog
and found that it was not installed. However, when I look at the /dev
directory, I actually found two watchdogs:
watchdog
and watchdog0
I am curious. Do I actually own any watchdogs? Why does the kernel complain that it did not stop when I do a reboot?
Best Answer
Most modern PC hardware includes watchdog timer facilities. You can read more about them here via wikipedia: Watchdog Timers. Also from the Linux kernel docs:
excerpt - https://www.kernel.org/doc/Documentation/watchdog/watchdog-api.txt
This SO Q&A titled, Who is refreshing hardware watchdog in Linux?, covers the linkage between the Linux kernel and the hardware watchdog timer.
What about the watchdog package?
The description in the RPM makes this pretty clear, IMO. The
excerpt from RPM descriptionwatchdog
daemon can either act as a software watchdog or can interact with the hardware implementation.