- Watchdog Linux Wiki
- Watchdog Linux
- Download Free Linux Operating System
- Watchdog Linux Configuration
- Watchdog Linux Script
Watchdog driver for embedded systems with a supervisor watchdog (MAX823 or so) connected to a gpio. This is the platformdriver and needs platformdata for.
- Introduction A watchdog on Linux is usually exported through a character device under /dev/watchdog. A simple API allows opening the device to enable the watchdog. Writing to it triggers the watchdog, and if the device is not cleanly closed, the watchdog will reboot the system.
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Name
watchdog.conf - configuration file for the watchdog daemon
Description
This file carries all configuration options for the Linux watchdog daemon. Each option has to be written on a line for itself. Comments start with '#'.Blanks are ignored except after the '=' sign. An empty text after the '=' sign disables the feature as long as that makes sense.
Options
interval =
- max-load-1 =
- Set the maximal allowed load average for a 1 minute span. Once this load average is reached the system is rebooted. Default value is 0. That means the loadaverage check is disabled. Be careful not to this parameter too low. To set a value less then the predefined minimal value of 2, you have to use the -fcommandline option.
- max-load-5 =
- Set the maximal allowed load average for a 5 minute span. Once this load average is reached the system is rebooted. Default value is 3/4*max-load-1. Becareful not to this parameter too low. To set a value less then the predefined minimal value of 2, you have to use the -f commandline option.
- max-load-15 =
- Set the maximal allowed load average for a 15 minute span. Once this load average is reached the system is rebooted. Default value is 1/2*max-load-1. Becareful not to this parameter too low. To set a value less then the predefined minimal value of 2, you have to use the -f commandline option.
- min-memory =
- Set the minimal amount of virtual memory that has to stay free. Note that this is in pages. Default value is 0 pages which means this test is disabled. Thepage size is taken from the system include files.
- max-temperature =
- Set the maximal allowed temperature. Once this temperature is reached the system is halted. Default value is 120. There is no unit conversion, so make sureyou use the same unit as your hardware. Watchdog will issue warnings once the temperature increases 90%, 95% and 98% of this temperature.
- watchdog-device =
- Set the watchdog device name. Default is to disable keep alive support.
- temperature-device =
- Set the temperature device name. Default is to disable temperature checking.
- file =
- Set file name for file mode. This option can be given as often as you like to check several files.
- change =
- Set the change interval time for file mode. This options always belongs to the active filename, that is when finding a 'change =' line watchdog assumes itbelongs to the most recently read 'file =' line. They don't neccessarily have to follow each other directly. But you cannot specify a 'change =' before a 'file='. The default is to only stat the file and don't look for changes.
- pidfile =
- Set pidfile name for server test mode. This option can be given as often as you like to check several servers.
- ping =
- Set IP address for ping mode. This option can be used more than once to check different connections.
- interface =
- Set interface name for network mode. This option can be used more than once to check different interfaces.
- test-binary =
- Execute the given binary to do some user defined tests.
- test-timeout =
- User defined tests may only run for seconds. Set to 0 for unlimited.
- repair-binary =
- Execute the given binary in case of a problem instead of shutting down the system.
- admin =
- Email address to send admin mail to. That is, who shall be notified that the machine is being halted or rebooted. Default is 'root'. If you want to disablenotification via email just set admin to en empty string.
- realtime =
- If set to yes watchdog will lock itself into memory so it is never swapped out.
- priority =
- Set the schedule priority for realtime mode.
- test-directory =
- Set the directory to run user test/repair scripts. Default is '/etc/watchdog.d' See the Test Directory section in watchdog(8) for moreinformation.
Files
/etc/watchdog.conf
Referenced By
Watchdog Linux Wiki
wd_keepalive(8)Watchdog Linux
The Linux kernel can reset the system if serious problems are detected. This can be implemented via special watchdog hardware, or via a slightly less reliable software-only watchdog inside the kernel. Either way, there needs to be a daemon that tells the kernel the system is working fine. If the daemon stops doing that, the system is reset.
watchdog is such a daemon. It 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 the watchdog hardware will cause the reset. In the case of the software watchdog the ability to reboot will depend on the state of the machines and interrupts.
The watchdog 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.
Tests
The watchdog daemon does several tests to check the system status:
- Is the process table full?
- Is there enough free memory?
- Are some files accessible?
- Have some files changed within a given interval?
- Is the average work load too high?
- Has a file table overflow occurred?
- Is a process still running? The process is specified by a pid file.
- Do some IP addresses answer to ping?
- Do network interfaces receive traffic?
- Is the temperature too high? (Temperature data not always available.)
- Execute a user defined command to do arbitrary tests. If any of these checks fail watchdog will cause a shutdown. Should any of these tests except the user defined binary last longer than one minute the machine will be rebooted, too.
Installation
watchdog can be installed with the Pakfire web interface or via the console:
Configuration
Download Free Linux Operating System
- Install addon via pakfire. After installation the addon is disabled by default.
- Create /etc/sysconfig/watchdog
Watchdog Linux Configuration
- Edit configuration file /etc/watchdog.conf
Name
watchdog.conf - configuration file for the watchdog daemon
Description
This file carries all configuration options for the Linux watchdog daemon. Each option has to be written on a line for itself. Comments start with '#'.Blanks are ignored except after the '=' sign. An empty text after the '=' sign disables the feature as long as that makes sense.
Options
interval =
- max-load-1 =
- Set the maximal allowed load average for a 1 minute span. Once this load average is reached the system is rebooted. Default value is 0. That means the loadaverage check is disabled. Be careful not to this parameter too low. To set a value less then the predefined minimal value of 2, you have to use the -fcommandline option.
- max-load-5 =
- Set the maximal allowed load average for a 5 minute span. Once this load average is reached the system is rebooted. Default value is 3/4*max-load-1. Becareful not to this parameter too low. To set a value less then the predefined minimal value of 2, you have to use the -f commandline option.
- max-load-15 =
- Set the maximal allowed load average for a 15 minute span. Once this load average is reached the system is rebooted. Default value is 1/2*max-load-1. Becareful not to this parameter too low. To set a value less then the predefined minimal value of 2, you have to use the -f commandline option.
- min-memory =
- Set the minimal amount of virtual memory that has to stay free. Note that this is in pages. Default value is 0 pages which means this test is disabled. Thepage size is taken from the system include files.
- max-temperature =
- Set the maximal allowed temperature. Once this temperature is reached the system is halted. Default value is 120. There is no unit conversion, so make sureyou use the same unit as your hardware. Watchdog will issue warnings once the temperature increases 90%, 95% and 98% of this temperature.
- watchdog-device =
- Set the watchdog device name. Default is to disable keep alive support.
- temperature-device =
- Set the temperature device name. Default is to disable temperature checking.
- file =
- Set file name for file mode. This option can be given as often as you like to check several files.
- change =
- Set the change interval time for file mode. This options always belongs to the active filename, that is when finding a 'change =' line watchdog assumes itbelongs to the most recently read 'file =' line. They don't neccessarily have to follow each other directly. But you cannot specify a 'change =' before a 'file='. The default is to only stat the file and don't look for changes.
- pidfile =
- Set pidfile name for server test mode. This option can be given as often as you like to check several servers.
- ping =
- Set IP address for ping mode. This option can be used more than once to check different connections.
- interface =
- Set interface name for network mode. This option can be used more than once to check different interfaces.
- test-binary =
- Execute the given binary to do some user defined tests.
- test-timeout =
- User defined tests may only run for seconds. Set to 0 for unlimited.
- repair-binary =
- Execute the given binary in case of a problem instead of shutting down the system.
- admin =
- Email address to send admin mail to. That is, who shall be notified that the machine is being halted or rebooted. Default is 'root'. If you want to disablenotification via email just set admin to en empty string.
- realtime =
- If set to yes watchdog will lock itself into memory so it is never swapped out.
- priority =
- Set the schedule priority for realtime mode.
- test-directory =
- Set the directory to run user test/repair scripts. Default is '/etc/watchdog.d' See the Test Directory section in watchdog(8) for moreinformation.
Files
/etc/watchdog.conf
- Is the process table full?
- Is there enough free memory?
- Are some files accessible?
- Have some files changed within a given interval?
- Is the average work load too high?
- Has a file table overflow occurred?
- Is a process still running? The process is specified by a pid file.
- Do some IP addresses answer to ping?
- Do network interfaces receive traffic?
- Is the temperature too high? (Temperature data not always available.)
- Execute a user defined command to do arbitrary tests. If any of these checks fail watchdog will cause a shutdown. Should any of these tests except the user defined binary last longer than one minute the machine will be rebooted, too.
- Install addon via pakfire. After installation the addon is disabled by default.
- Create /etc/sysconfig/watchdog
- Edit configuration file /etc/watchdog.conf
- watchdog(8) - Linux man page on die.net
- The main page of watchdog
- Linux Watchdog -
- good resource for watchdog info
Referenced By
Watchdog Linux Wiki
wd_keepalive(8)Watchdog Linux
The Linux kernel can reset the system if serious problems are detected. This can be implemented via special watchdog hardware, or via a slightly less reliable software-only watchdog inside the kernel. Either way, there needs to be a daemon that tells the kernel the system is working fine. If the daemon stops doing that, the system is reset.
watchdog is such a daemon. It 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 the watchdog hardware will cause the reset. In the case of the software watchdog the ability to reboot will depend on the state of the machines and interrupts.
The watchdog 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.
Tests
The watchdog daemon does several tests to check the system status:
Installation
watchdog can be installed with the Pakfire web interface or via the console:
Configuration
Download Free Linux Operating System
Watchdog Linux Configuration
Links
Watchdog Linux Script
