freebsd man page for reboot

REBOOT(8)						    BSD System Manager's Manual 						 REBOOT(8)

NAME
     reboot, halt, fastboot, fasthalt -- stopping and restarting the system

SYNOPSIS
     halt [-lnpq] [-k kernel]
     reboot [-dlnpq] [-k kernel]
     fasthalt [-lnpq] [-k kernel]
     fastboot [-dlnpq] [-k kernel]

DESCRIPTION
     The halt and reboot utilities flush the file system cache to disk, send all running processes a SIGTERM (and subsequently a SIGKILL) and,
     respectively, halt or restart the system.	The action is logged, including entering a shutdown record into the user accounting database.

     The options are as follows:

     -d      The system is requested to create a crash dump.  This option is supported only when rebooting, and it has no effect unless a dump
	     device has previously been specified with dumpon(8).

     -k kernel
	     Boot the specified kernel on the next system boot.  If the kernel boots successfully, the default kernel will be booted on successive
	     boots, this is a one-shot option.	If the boot fails, the system will continue attempting to boot kernel until the boot process is
	     interrupted and a valid kernel booted.  This may change in the future.

     -l      The halt or reboot is not logged to the system log.  This option is intended for applications such as shutdown(8), that call reboot
	     or halt and log this themselves.

     -n      The file system cache is not flushed.  This option should probably not be used.

     -p      The system will turn off the power if it can.  If the power down action fails, the system will halt or reboot normally, depending on
	     whether halt or reboot was called.

     -q      The system is halted or restarted quickly and ungracefully, and only the flushing of the file system cache is performed (if the -n
	     option is not specified).	This option should probably not be used.

     The fasthalt and fastboot utilities are nothing more than aliases for the halt and reboot utilities.

     Normally, the shutdown(8) utility is used when the system needs to be halted or restarted, giving users advance warning of their impending
     doom and cleanly terminating specific programs.

SEE ALSO
     getutxent(3), boot(8), dumpon(8), nextboot(8), savecore(8), shutdown(8), sync(8)

HISTORY
     A reboot utility appeared in Version 6 AT&T UNIX.

BSD
								 October 11, 2010							       BSD