Table of Contents
Watchdog on Linux/Ubuntu
Watchdog timers are commonly found in embedded systems and other computer-controlled equipment where humans cannot easily access the equipment or would be unable to react to faults in a timely manner. In such systems, the computer cannot depend on a human to reboot it if it hangs; it must be self-reliant.
ODROID-XU3/XU4 kernel support s3c2410_wdt module to control the Power Management Unit (PMU).
s3c2410_wdt driver is build as a loadable module so that watchdog daemon can configure the driver.
s3c2410_wdt could be loader with per-configurable parameters.
- tmr_margin - Watchdog tmr_margin in seconds.
- tmr_atboot - Watchdog is started at boot time if set to 1
- nowayout - Watchdog cannot be stopped once started
- soft_noboot - Watchdog action, set to 1 to ignore reboots
Note that the watchdog driver is available in the Kernel update 3.10.82-52 or higher.
odroid@odroid:~$ uname -a Linux odroid 3.10.82-52 #1 SMP PREEMPT Thu Aug 27 11:45:33 BRT 2015 armv7l armv7l armv7l GNU/Linux
Test Watchdog module
Watchdog driver s3c2410_wdt is configurable for Odroid XU3/XU4.
# sudo modprobe s3c2410_wdt
You should be able to see /dev/watchdog and /dev/watchdog0 device files being created.
# ls -l /dev/watchdog* crw------- 1 root root 10, 130 Aug 28 09:57 /dev/watchdog crw------- 1 root root 253, 0 Aug 28 09:57 /dev/watchdog0
Watchdog daemon will trigger and reboot if we access the device file manually.
# cat /dev/watchdog [ 7639.726211] watchdog watchdog0: watchdog did not stop!
To manually stop watchdog to reboot.
# echo V > /dev/watchdog
Install Watchdog daemon
To install watchdog daemon
sudo apt-get install watchdog
Create dir for watchdog logs files
sudo mkdir -p /var/log/watchdog
Remove the watchdog module from black list. /etc/modprobe.d/blacklist-watchdog.conf
Append the default watchdog configuration. /etc/default/watchdog
# Start watchdog at boot time? 0 or 1 run_watchdog=1 # Start wd_keepalive after stopping watchdog? 0 or 1 run_wd_keepalive=1 # Load module before starting watchdog watchdog_module=s3c2410_wdt # Specify additional watchdog options here (see manpage). watchdog_options="-s -v -c /etc/watchdog.conf"
Watchdog demon configuration files
Note: Watchdog drivers start automatically as it's buildin, but only if a watchdog daemon to configure the times.
You need to edit the /etc/watchdog.conf file to un-comment and so actually use the /dev/watchdog device access to the module. Otherwise the watchdog will not use the hardware and rely only on its internal code to soft-reboot a broken machine
$ cat /etc/watchdog.conf #ping = 172.31.14.1 #ping = 172.26.1.255 #interface = eth0 file = /var/log/syslog #change = 1407 # Uncomment to enable test. Setting one of these values to '0' disables it. # These values will hopefully never reboot your machine during normal use # (if your machine is really hung, the loadavg will go much higher than 25) #max-load-1 = 24 #max-load-5 = 18 #max-load-15 = 12 # Note that this is the number of pages! # To get the real size, check how large the pagesize is on your machine. #min-memory = 1 #allocatable-memory = 1 #repair-binary = /usr/sbin/repair #repair-timeout = #test-binary = #test-timeout = watchdog-device = /dev/watchdog # Defaults compiled into the binary #temperature-device = #max-temperature = 120 # Defaults compiled into the binary admin = root interval = 1 logtick = 1 log-dir = /var/log/watchdog # This greatly decreases the chance that watchdog won't be scheduled before # your machine is really loaded #realtime = yes #priority = 1 # Check if rsyslogd is still running by enabling the following line #pidfile = /var/run/rsyslogd.pid # set watchdog timer watchdog-timeout = 15 # set heartbeat setting heartbeat-file = /var/log/watchdog/heartbeat.log heartbeat-stamps = 300
For more configuration please follow link below. http://www.sat.dundee.ac.uk/psc/watchdog/watchdog-configure.html
Start Watchdog Service and Verify
Watchdog service somehow doesn't start automatically. For now if the service doesn't start, it can be started with small HACK.
root@odroidxu4m:~# cat /etc/rc.local #!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. service watchdog restart exit 0
Verify watchdog service in running correctly
root@odroidxu4m:~# service watchdog status ● watchdog.service - watchdog daemon Loaded: loaded (/lib/systemd/system/watchdog.service; static; vendor preset: enabled) Active: active (running) since Fri 2015-08-28 10:48:41 UTC; 2s ago Process: 4736 ExecStart=/bin/sh -c [ $run_watchdog != 1 ] || exec /usr/sbin/watchdog $watchdog_options (code=exited, status=0/SUCCESS) Main PID: 4738 (watchdog) CGroup: /system.slice/watchdog.service └─4738 /usr/sbin/watchdog -s -v -c /etc/watchdog.conf Aug 28 10:48:41 odroidxu4m watchdog: hardware watchdog identity: S3C2410 Watchdog Aug 28 10:48:41 odroidxu4m systemd: Started watchdog daemon. Aug 28 10:48:41 odroidxu4m watchdog: current load is 0 0 0 Aug 28 10:48:41 odroidxu4m watchdog: was able to ping process 2033 (/var/run/rsyslogd.pid). Aug 28 10:48:42 odroidxu4m watchdog: still alive after 1 interval(s) Aug 28 10:48:42 odroidxu4m watchdog: current load is 0 0 0 Aug 28 10:48:42 odroidxu4m watchdog: was able to ping process 2033 (/var/run/rsyslogd.pid). Aug 28 10:48:43 odroidxu4m watchdog: still alive after 2 interval(s) Aug 28 10:48:43 odroidxu4m watchdog: current load is 0 0 0 Aug 28 10:48:43 odroidxu4m watchdog: was able to ping process 2033 (/var/run/rsyslogd.pid).