freebsd-dev/usr.sbin/watchdogd/watchdogd.8
Sean Kelly 370c3cb57c - Add a software watchdog facility.
This commit has two pieces. One half is the watchdog kernel code which lives
primarily in hardclock() in sys/kern/kern_clock.c. The other half is a userland
daemon which, when run, will keep the watchdog from firing while the userland
is intact and functioning.

Approved by:	jeff (mentor)
2003-06-26 09:50:52 +00:00

98 lines
2.8 KiB
Groff

.\" Copyright (c) 2003 Sean M. Kelly <smkelly@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
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.\" $FreeBSD$
.\"
.Dd June 25, 2003
.Dt WATCHDOGD 8
.Os
.Sh NAME
.Nm watchdogd
.Nd Software watchdog daemon
.Sh SYNOPSIS
.Nm
.Op Fl d
.Op Fl I Ar file
.Sh DESCRIPTION
The
.Nm
utility interfaces with the kernel's software watchdog facility to ensure
that the system is in a working state.
If
.Nm
is unable to interface with the kernel over a specific timeout,
the kernel will take actions to assist in debugging or restarting the computer.
.Pp
One possible circumstance which will cause a watchdog timeout is an interrupt
storm.
If this occurs,
.Nm
will no longer execute and thus the kernel's watchdog routines will take
action after a configurable timeout.
.Pp
Upon receiving the
.Dv SIGTERM
or
.Dv SIGINT
signals,
.Nm
will first instruct the kernel to no longer perform watchdog checks and then
will terminate.
.Pp
The
.Nm
utility recognizes the following runtime options:
.Bl -tag -width ".Fl I Ar file"
.It Fl I Ar file
Write the process id of the
.Nm
utility in the specified file.
.It Fl d
Don't fork.
When this option is specified,
.Nm
will not fork into the background at startup.
.El
.Sh FILES
.Bl -tag -width "/var/run/watchdogd.pid" -compact
.It Pa /var/run/watchdogd.pid
.El
.Sh SEE ALSO
.Xr watchdog 4 ,
.Xr sysctl 8
.Sh AUTHORS
.An -nosplit
The
.Nm
utility and manual page were written by
.An Sean Kelly Aq smkelly@FreeBSD.org .
.Pp
Some contributions made by
.An Jeff Roberson Aq jeff@FreeBSD.org .
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 5.1 .