1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)reboot.8 8.1 (Berkeley) 6/9/93 29.\" $FreeBSD: src/sbin/reboot/reboot.8,v 1.10.2.7 2003/02/23 22:42:10 trhodes Exp $ 30.\" $DragonFly: src/sbin/reboot/reboot.8,v 1.3 2005/08/01 01:49:17 swildner Exp $ 31.\" 32.Dd June 9, 1993 33.Dt REBOOT 8 34.Os 35.Sh NAME 36.Nm reboot , 37.Nm halt , 38.Nm fastboot , 39.Nm fasthalt 40.Nd stopping and restarting the system 41.Sh SYNOPSIS 42.Nm halt 43.Op Fl lnqp 44.Op Fl k Ar kernel 45.Nm 46.Op Fl dlnqp 47.Op Fl k Ar kernel 48.Nm fasthalt 49.Op Fl lnqp 50.Op Fl k Ar kernel 51.Nm fastboot 52.Op Fl dlnqp 53.Op Fl k Ar kernel 54.Sh DESCRIPTION 55The 56.Nm halt 57and 58.Nm 59utilities flush the file system cache to disk, send all running processes 60a 61.Dv SIGTERM 62(and subsequently a 63.Dv SIGKILL ) 64and, respectively, halt or restart the system. 65The action is logged, including entering a shutdown record into the 66.Xr wtmp 5 67file. 68.Pp 69The options are as follows: 70.Bl -tag -width indent 71.It Fl d 72The system is requested to create a crash dump. 73This option is 74supported only when rebooting, and it has no effect unless a dump 75device has previously been specified with 76.Xr dumpon 8 . 77.It Fl k Ar kernel 78Boot the specified 79.Ar kernel 80on the next system boot. 81If the kernel boots successfully, the 82.Em default 83kernel will be booted on successive boots, this is a one-shot option. 84If the boot fails, the system will continue attempting to boot 85.Ar kernel 86until the boot process is interrupted and a valid kernel booted. 87This may change in the future. 88.It Fl l 89The halt or reboot is 90.Em not 91logged to the system log. 92This option is intended for applications such as 93.Xr shutdown 8 , 94that call 95.Nm 96or 97.Nm halt 98and log this themselves. 99.It Fl n 100The file system cache is not flushed. 101This option should probably not be used. 102.It Fl q 103The system is halted or restarted quickly and ungracefully, and only 104the flushing of the file system cache is performed (if the 105.Fl n 106is not specified). 107This option should probably not be used. 108.It Fl p 109The system will turn off the power 110if it can. 111This is of course likely to make 112.Nm 113rather similar to 114.Nm halt . 115.El 116.Pp 117The 118.Nm fasthalt 119and 120.Nm fastboot 121utilities are nothing more than aliases for the 122.Nm halt 123and 124.Nm 125utilities. 126.Pp 127Normally, the 128.Xr shutdown 8 129utility is used when the system needs to be halted or restarted, giving 130users advance warning of their impending doom and cleanly terminating 131specific programs. 132.Sh SEE ALSO 133.Xr wtmp 5 , 134.Xr boot 8 , 135.Xr dumpon 8 , 136.Xr savecore 8 , 137.Xr shutdown 8 , 138.Xr sync 8 139.Sh HISTORY 140A 141.Nm 142command appeared in 143.At v6 . 144