HALT(8) 	      Linux System Administrators Manual	      HALT(8)



NAME
       halt, reboot, poweroff - stop the system.

SYNOPSIS
       /sbin/halt [-n] [-w] [-d] [-f] [-i] [-p] [-h]
       /sbin/reboot [-n] [-w] [-d] [-f] [-i]
       /sbin/poweroff [-n] [-w] [-d] [-f] [-i] [-h]

DESCRIPTION
       Halt  notes  that  the  system  is  being  brought  down  in  the  file
       /var/log/wtmp, and then either tells the  kernel  to  halt,  reboot  or
       power-off the system.

       If  halt or reboot is called when the system is not in runlevel 0 or 6,
       in other words when its running normally,  shutdown  will  be  invoked
       instead	(with  the  -h	or -r flag). For more info see the shutdown(8)
       manpage.

       The rest of this manpage describes the behaviour in runlevels 0 and  6,
       that is when the systems shutdown scripts are being run.

OPTIONS
       -n     Dont sync before reboot or halt.

       -w     Dont actually reboot or halt but only write the wtmp record (in
	      the /var/log/wtmp file).

       -d     Dont write the wtmp record. The -n flag implies -d.

       -f     Force halt or reboot, dont call shutdown(8).

       -i     Shut down all network interfaces just before halt or reboot.

       -h     Put all hard drives on the system in stand-by mode  just	before
	      halt or power-off.

       -p     When  halting  the  system,  switch  off	the power. This is the
	      default when halt is called as poweroff.

DIAGNOSTICS
       If youre not the superuser, you will get the message  must  be  supe
       ruser.

NOTES
       Under  older sysvinit releases , reboot and halt should never be called
       directly. From release 2.74 on halt and reboot  invoke  shutdown(8)  if
       the system is not in runlevel 0 or 6. This means that if halt or reboot
       cannot find out the current runlevel (for example,  when  /var/run/utmp
       hasnt been initialized correctly) shutdown will be called, which might
       not be what you want.  Use the -f flag if you want to do a hard halt or
       reboot.

       The  -h	flag  puts  all hard disks in standby mode just before halt or
       power-off. Right now this is only implemented for IDE  drives.  A  side
       effect of putting the drive in stand-by mode is that the write cache on
       the disk is flushed. This is important for IDE drives, since the kernel
       doesnt flush the write cache itself before power-off.

       The halt program uses /proc/ide/hd* to find all IDE disk devices, which
       means that /proc needs to be mounted when halt or poweroff is called or
       the -h switch will do nothing.


AUTHOR
       Miquel van Smoorenburg, miquels@cistron.nl

SEE ALSO
       shutdown(8), init(8)



				  Nov 6, 2001			       HALT(8)