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wdmd(8) [centos man page]

WDMD(8) 						      System Manager's Manual							   WDMD(8)

NAME
wdmd - watchdog multiplexing daemon SYNOPSIS
wdmd [OPTIONS] DESCRIPTION
This daemon opens /dev/watchdog and allows multiple independent sources to detmermine whether each KEEPALIVE is done. Every test interval (10 seconds), the daemon tests each source. If any test fails, the KEEPALIVE is not done. In a standard configuration, the watchdog timer will reset the system if no KEEPALIVE is done for 60 seconds ("fire timeout"). This means that if a single test fails 5-6 times in row, the watchdog will fire and reset the system. With multiple test sources, fewer separate failures back to back can also cause a reset, e.g. T seconds, P pass, F fail T00: test1 P, test2 P, test3 P: KEEPALIVE done T10: test1 F, test2 F, test3 P: KEEPALIVE skipped T20: test1 F, test2 P, test3 P: KEEPALIVE skipped T30: test1 P, test2 F, test3 P: KEEPALIVE skipped T40: test1 P, test2 P, test3 F: KEEPALIVE skipped T50: test1 F, test2 F, test3 P: KEEPALIVE skipped T60: test1 P, test2 F, test3 P: KEEPALIVE skipped T60: watchdog fires, system resets (Depending on timings, the system may be reset sometime shortly before T60, and the tests at T60 would not be run.) A crucial aspect to the design and function of wdmd is that if any single source does not pass tests for the fire timeout, the watchdog is guaranteed to fire, regardless of whether other sources on the system have passed or failed. A spurious reset due to the combined effects of multiple failing tests as shown above, is an accepted side effect. The wdmd init script will load the softdog module if no other watchdog module has been loaded. wdmd cannot be used on the system with any other program that needs to open /dev/watchdog, e.g. watchdog(8). Test Source: clients Using libwdmd, programs connect to wdmd via a unix socket, and send regular messages to wdmd to update an expiry time for their connection. Every test interval, wdmd will check if the expiry time for a connection has been reached. If so, the test for that client fails. Test Source: scripts wdmd will run scripts from a designated directory every test interval. If a script exits with 0, the test is considered a success, other- wise a failure. If a script does not exit by the end of the test interval, it is considered a failure. OPTIONS
--version, -V Print version. --help, -h Print usage. --dump, -d Print debug information from the daemon. --probe, -p Print path of functional watchdog device. Exit code 0 indicates a functional device was found. Exit code 1 indicates a functional device was not found. -D Enable debugging to stderr and don't fork. -H 0|1 Enable (1) or disable (0) high priority features such as realtime scheduling priority and mlockall. -G name Group ownership for the socket. -S 0|1 Enable (1) or disable (0) script tests. -s path Path to scripts dir. -k num Kill unfinished scripts after num seconds. -w path The path to the watchdog device to try first. 2011-08-01 WDMD(8)

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WATCHDOG.CONF(5)						File Formats Manual						  WATCHDOG.CONF(5)

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 = <interval> Set the interval between two writes to the watchdog device. The kernel drivers expects a write command every minute. Otherwise the system will be rebooted. Default value is 1 second. An interval of more than a minute can only be used with the -f command-line option. logtick = <logtick> If you enable verbose logging, a message is written into the syslog or a logfile. While this is nice, it is not necessary to get a message every 10 seconds which really fills up disk and needs CPU. logtick allows adjustment of the number of intervals skipped before a log message is written. If you use logtick = 60 and interval = 10, only every 10 minutes (600 seconds) a message is writ- ten. This may make the exact time of a crash harder to find but greatly reduces disk usage and administrator nerves if you're look- ing for a particular syslog entry in between of watchdog messages. max-load-1 = <load1> 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 load average 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 -f commandline option. max-load-5 = <load5> 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. 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 -f commandline option. max-load-15 = <load15> 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. 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 -f commandline option. min-memory = <minpage> 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. The page size is taken from the system include files. max-temperature = <temp> 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 sure you use the same unit as your hardware. Watchdog will issue warnings once the temperature increases 90%, 95% and 98% of this temperature. watchdog-device = <device> Set the watchdog device name. Default is to disable keep alive support. watchdog-timeout = <timeout> Set the watchdog device timeout during startup. If not set, the default is driver-dependent. temperature-device = <temp-dev> Set the temperature device name. Default is to disable temperature checking. file = <filename> Set file name for file mode. This option can be given as often as you like to check several files. change = <mtime> 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 it belongs 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. Using this feature to monitor changes in /var/log/messages might require some special syslog daemon configuration, e.g. rsyslog needs "$ActionWriteAllMarkMessages on" to be set to make sure the marks are written no matter what. pidfile = <pidfilename> Set pidfile name for server test mode. This option can be given as often as you like to check several servers. ping = <ip-addr> Set IP address for ping mode. This option can be used more than once to check different connections. interface = <if-name> Set interface name for network mode. This option can be used more than once to check different interfaces. test-binary = <testbin> Execute the given binary to do some user defined tests. test-timeout = <timeout in seconds> User defined tests may only run for <timeout> seconds. Set to 0 for unlimited. repair-binary = <repbin> Execute the given binary in case of a problem instead of shutting down the system. repair-timeout = <timeout in seconds> repair command may only run for <timeout> seconds. Set to 0 for unlimited. admin = <mail-address> 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 disable notification via email just set admin to en empty string. realtime = <yes|no> If set to yes watchdog will lock itself into memory so it is never swapped out. priority = <schedule priority> Set the schedule priority for realtime mode. test-directory = <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 more information. log-dir = <log directory> Set the log directory to capture the standard output and standard error from repair-binary and test-binary execution. Default is '/var/log/watchdog'. FILES
/etc/watchdog.conf The watchdog configuration file /etc/watchdog.d A directory containing test-or-repair commands. See the Test Directory section in watchdog(8) for more information. SEE ALSO
watchdog(8) 4th Berkeley Distribution January 2005 WATCHDOG.CONF(5)

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