xref: /freebsd/usr.sbin/watchdogd/watchdogd.8 (revision 9cdb6ee1641e84242a1640055e0072ad693e1a7d)
1.\" Copyright (c) 2004  Poul-Henning Kamp <phk@FreeBSD.org>
2.\" Copyright (c) 2003  Sean M. Kelly <smkelly@FreeBSD.org>
3.\" All rights reserved.
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26.\" $FreeBSD$
27.\"
28.Dd June 25, 2003
29.Dt WATCHDOGD 8
30.Os
31.Sh NAME
32.Nm watchdogd
33.Nd watchdog daemon
34.Sh SYNOPSIS
35.Nm
36.Op Fl d
37.Op Fl e Ar cmd
38.Op Fl I Ar file
39.Op Fl s Ar sleep
40.Op Fl t Ar timeout
41.Sh DESCRIPTION
42The
43.Nm
44utility interfaces with the kernel's watchdog facility to ensure
45that the system is in a working state.
46If
47.Nm
48is unable to interface with the kernel over a specific timeout,
49the kernel will take actions to assist in debugging or restarting the computer.
50.Pp
51If
52.Fl e Ar cmd
53is specified,
54.Nm
55will attempt to execute this command with
56.Xr system 3 ,
57and only if the command returns with a zero exit code will the
58watchdog be reset.
59If
60.Fl e Ar cmd
61is not specified, the daemon will perform a trivial file system
62check instead.
63.Pp
64The
65.Fl s Ar sleep
66argument can be used to control the sleep period between each execution
67of the check and defaults to one second.
68.Pp
69The
70.Fl t Ar timeout
71specifies the desired timeout period in seconds.
72.Pp
73One possible circumstance which will cause a watchdog timeout is an interrupt
74storm.
75If this occurs,
76.Nm
77will no longer execute and thus the kernel's watchdog routines will take
78action after a configurable timeout.
79.Pp
80Upon receiving the
81.Dv SIGTERM
82or
83.Dv SIGINT
84signals,
85.Nm
86will first instruct the kernel to no longer perform watchdog checks and then
87will terminate.
88.Pp
89The
90.Nm
91utility recognizes the following runtime options:
92.Bl -tag -width ".Fl I Ar file"
93.It Fl I Ar file
94Write the process ID of the
95.Nm
96utility in the specified file.
97.It Fl d
98Do not fork.
99When this option is specified,
100.Nm
101will not fork into the background at startup.
102.El
103.Sh FILES
104.Bl -tag -width ".Pa /var/run/watchdogd.pid" -compact
105.It Pa /var/run/watchdogd.pid
106.El
107.Sh SEE ALSO
108.Xr watchdog 4 ,
109.Xr watchdog 8 ,
110.Xr watchdog 9
111.Sh AUTHORS
112.An -nosplit
113The
114.Nm
115utility and manual page were written by
116.An Sean Kelly Aq smkelly@FreeBSD.org
117and
118.An Poul-Henning Kamp Aq phk@FreeBSD.org .
119.Pp
120Some contributions made by
121.An Jeff Roberson Aq jeff@FreeBSD.org .
122.Sh HISTORY
123The
124.Nm
125utility appeared in
126.Fx 5.1 .
127