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.\" 31.Dd September 29, 2016 32.Dt REBOOT 8 33.Os 34.Sh NAME 35.Nm reboot , 36.Nm halt , 37.Nm fastboot , 38.Nm fasthalt 39.Nd stopping and restarting the system 40.Sh SYNOPSIS 41.Nm halt 42.Op Fl lnqp 43.Op Fl k Ar kernel 44.Nm 45.Op Fl dlnqp 46.Op Fl k Ar kernel 47.Nm fasthalt 48.Op Fl lnqp 49.Op Fl k Ar kernel 50.Nm fastboot 51.Op Fl dlnqp 52.Op Fl k Ar kernel 53.Sh DESCRIPTION 54The 55.Nm halt 56and 57.Nm 58utilities flush the file system cache to disk, send all running processes 59a 60.Dv SIGTERM 61(and subsequently a 62.Dv SIGKILL ) 63and, respectively, halt or restart the system. 64The action is logged, including entering a shutdown record into the 65.Xr wtmp 5 66file. 67.Pp 68The options are as follows: 69.Bl -tag -width indent 70.It Fl d 71The system is requested to create a crash dump. 72This option is 73supported only when rebooting, and it has no effect unless a dump 74device has previously been specified with 75.Xr dumpon 8 . 76.It Fl k Ar kernel 77Boot the specified 78.Ar kernel 79on the next system boot. 80If the kernel boots successfully, the 81.Em default 82kernel will be booted on successive boots, this is a one-shot option. 83If the boot fails, the system will continue attempting to boot 84.Ar kernel 85until the boot process is interrupted and a valid kernel booted. 86This may change in the future. 87.It Fl l 88The halt or reboot is 89.Em not 90logged to the system log. 91This option is intended for applications such as 92.Xr shutdown 8 , 93that call 94.Nm 95or 96.Nm halt 97and log this themselves. 98.It Fl n 99The file system cache is not flushed. 100This option should probably not be used. 101.It Fl q 102The system is halted or restarted quickly and ungracefully, and only 103the flushing of the file system cache is performed (if the 104.Fl n 105is not specified). 106This option should probably not be used. 107.It Fl p 108The system will turn off the power 109if it can. 110This is of course likely to make 111.Nm 112rather similar to 113.Nm halt . 114.El 115.Pp 116The 117.Nm fasthalt 118and 119.Nm fastboot 120utilities are nothing more than aliases for the 121.Nm halt 122and 123.Nm 124utilities. 125.Pp 126Normally, the 127.Xr shutdown 8 128utility is used when the system needs to be halted or restarted, giving 129users advance warning of their impending doom and cleanly terminating 130specific programs. 131.Sh SEE ALSO 132.Xr wtmp 5 , 133.Xr boot 8 , 134.Xr dumpon 8 , 135.Xr savecore 8 , 136.Xr shutdown 8 , 137.Xr sync 8 138.Sh HISTORY 139A 140.Nm 141command appeared in 142.Bx 4.0 . 143