1.\" $NetBSD: reboot.8,v 1.17 2002/10/03 15:41:45 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)reboot.8 8.1 (Berkeley) 6/9/93 35.\" 36.Dd April 14, 2000 37.Dt REBOOT 8 38.Os 39.Sh NAME 40.Nm reboot , 41.Nm poweroff , 42.Nm halt 43.Nd restarting, powering down and stopping the system 44.Sh SYNOPSIS 45.Nm halt 46.Op Fl dlnpq 47.Nm poweroff 48.Op Fl dlnq 49.Nm "" 50.Op Fl dlnq 51.Sh DESCRIPTION 52The 53.Nm poweroff , 54.Nm halt 55and 56.Nm 57utilities flush the file system cache to disk, send all running processes 58a SIGTERM, wait up to 30 seconds for them to die, send a SIGKILL to the 59survivors and, respectively, power down, halt or restart the system. 60The action is logged, including entering a shutdown record into the login 61accounting file and sending a message via 62.Xr syslog 3 . 63.Pp 64The options are as follows: 65.Bl -tag -width Ds 66.It Fl d 67Create a dump before halting or restarting. 68This option is useful for debugging system dump procedures or 69capturing the state of a corrupted or misbehaving system. 70.It Fl l 71Suppress sending a message via 72.Xr syslog 3 73before halting or restarting. 74.It Fl n 75Do not flush the file system cache. 76This option should be used with extreme caution. 77It can be used if a disk or the processor is on fire. 78.It Fl p 79Attempt to powerdown the system. 80If the powerdown fails, or the system does not support 81software powerdown, the system will halt. 82This option is only valid for 83.Nm halt . 84.It Fl q 85Do not give processes a chance to shut down before halting or restarting. 86This option should not normally be used. 87.El 88.Pp 89Normally, the 90.Xr shutdown 8 91utility is used when the system needs to be halted or restarted, giving 92users advance warning of their impending doom. 93.Sh SEE ALSO 94.Xr reboot 2 , 95.Xr syslog 3 , 96.Xr utmp 5 , 97.Xr boot 8 , 98.Xr shutdown 8 , 99.Xr sync 8 100.Sh HISTORY 101A 102.Nm 103command appeared in 104.At v6 . 105.Pp 106The 107.Nm poweroff 108command first appeared in 109.Nx 1.5 . 110.Sh BUGS 111The single user shell will ignore the SIGTERM signal. 112To avoid waiting for the timeout when 113rebooting or halting from the single user shell, you have to 114.Ic exec reboot 115or 116.Ic exec halt . 117