watchdogtimerd(8) System Manager's Manual watchdogtimerd(8)
NAME
watchdogtimerd -- Mac OS X Server automatic reboot daemon (hardware watchdog tickler)
SYNOPSIS
watchdogtimerd [-d | -n | -R] [-i interval] [-c count] [-L facility]
watchdogtimerd [-h | -v]
DESCRIPTION
watchdogtimerd is indirectly responsible for rebooting the server hardware if the machine hangs or pan-ics. panics.
ics. When watchdogtimerd runs on supported hardware, it periodically resets the hardware watchdog
timer. If the timer ever expires, the power management unit forces a hard reboot. Automatic reboot is
disabled when watchdogtimerd quits cleanly, so it is imperative watchdogtimerd be terminated by sending
a termination signal (SIGTERM), NOT a kill signal (SIGKILL)!
watchdogtimerd is typically launched at boot time under the control of launchd(8) using the job label
com.apple.watchdogtimerd.
OPTIONS
The following options are available:
-c count
--cycles=count Reboot the machine if the timer has not been reset for count intervals. This
option is primarily used when debugging. Valid range of values is 3 through 480.
Default is 6, resulting in a reboot within five minutes after failure.
-d
--debug Print log strings to the terminal.
-h
--help Print usage summary and exit.
-i interval
--interval=interval Reset the watchdog timer every interval seconds. This option is primarily used
when debugging. Valid range of values is 1 through 30. Default is 30.
-L facility Enable logging to syslog(8) using the specified facility. The following values
for facility are supported: daemon (the default), user, local[0-7]. (See
syslog.conf(5) for their meanings.) This is equivalent to --syslog.
-n
--no-run Print log information to the terminal and quit after validating the hardware
watchdog timer.
-R
--reboot Force a hard reboot by initializing the watchdog timer to (count * interval) sec-onds seconds
onds and terminating.
--syslog=facility Enable logging to syslog(8) using the specified facility. The following values
for facility are supported: daemon (the default), auth, user, local[0-7]. (See
syslog.conf(5) for their meanings.) This is equivalent to -L.
-v
--version Print build version and exit.
FILES & FOLDERS
/usr/sbin/watchdogtimerd
- daemon
/System/Library/LaunchDaemons/com.apple.watchdogtimerd.plist
- launchd(8) configuration file.
DIAGNOSTICS
The watchdogtimerd utility exits 0 on success, and >0 if an error occurs. The following table lists
possible exit codes, their equivalent constants in sysexits(3), and their corresponding failure condi-tion. condition.
tion.
code constant failure condition
64 EX_USAGE invalid arguments
69 EX_UNAVAILABLE automatic reboot timer unavailable
77 EX_NOPERM insufficient permissions
Could not access automatic reboot timer. The executing machine does not support a hardware watchdog
timer.
Invalid interval. Valid intervals range from 1 to 30.
Invalid number of cycles. Valid cycles range from 3 to 480.
Unable to raise process priority. watchdogtimerd was unable to raise its priority. This may result in
inadvertant reboots if other (typically real-time) processes consume all available cycles.
watchdogtimerd must be executed as root. Because watchdogtimerd controls system-wide resources, it
must be executed by the root user.
SEE ALSO
sysexits(3), syslog.conf(5), launchctl(8), launchd(8), syslogd(8)
Apple's technical note TN2118: Kernel Core Dumps <http://developer.apple.com/technotes/tn2004/
tn2118.html describes how to set up a crash dump server and how to send dumps from panicked machines.
These instructions allow a site to record kernel panics for debugging or analysis while leveraging the
higher service availability provided by watchdogtimerd. This approach is recommended for most sites
instead of increasing the time before forcing a reboot.
KNOWN ISSUES
None identified at this time.
HISTORY
watchdogtimerd replaces the hardware watchdog timer servicing of watchdog(8).
The pressing question used to be, "Who watches the watchmen?" Now we know: launchd(8).
Mac OS X Server 10.5 May 1, 2007 Mac OS X Server 10.5
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