2.11BSD#431 - /usr/man/cat8/halt.0

REBOOT(8)	    UNIX Programmer's Manual		REBOOT(8)


NAME
     reboot - stopping and restarting the system

SYNOPSIS
     /sbin/reboot [ -lqnhdarsfRD ]
     /sbin/halt [ -lqndars ]
     /sbin/fastboot [ -lqndarsRD ]

DESCRIPTION
     2.11BSD is started by placing it in memory at location zero
     and transferring to its entry point.  Since the system is
     not reentrant, it is necessary to read it in from disk or
     tape each time it is to be boot strapped.

     Rebooting a running system: When the system is running and a
     reboot is desired, shutdown(8) is normally used to stop time
     sharing and put the system into single user mode.	If there
     are no users then /sbin/reboot can be used without shutting
     the system down first.

     Reboot normally causes the disks to be synced and allows the
     system to perform other shutdown activities such as resyn-
     chronizing hardware time-of-day clocks.  A multi-user reboot
     (as described below) is then initiated.  This causes a sys-
     tem to be booted and an automatic disk check to be per-
     formed.  If all this succeeds without incident, the system
     is then brought up for multi-user operation.

     Options to reboot are:

     -l   Don't try to tell syslogd(8) what's about to happen.

     -q   Reboot quickly and ungracefully, without shutting down
	  running processes first.

     -n   Don't sync before rebooting.	This can be used if a
	  disk or the processor is on fire.

     -h   Don't reboot, simply halt the processor.

     -d   Dump memory onto the dump device, usually part of swap,
	  before rebooting.  The dump is done in the same way as
	  after a panic.

     -a   Have the system booter ask for the name of the system
	  to be booted, rather than immediately booting the
	  default system (/unix).

     -r   Mount the root file system as read only when the system
	  reboots.  This is not supported by the kernel in
	  2.11BSD.


Printed 11/24/99	  May 24, 1996				1


REBOOT(8)	    UNIX Programmer's Manual		REBOOT(8)


     -s   Don't enter multi-user mode after system has rebooted -
	  stay in single user mode.

     -f   Fast reboot.	Omit the automatic file system con-
	  sistency check when the system reboots and goes multi-
	  user.  This is accomplished by passing a fast reboot
	  flag on to the rebooting kernel.  This currently
	  prevents the use of -f flag in conjunction with the -h
	  (halt) flag.

     -D   Set the autoconfig(8) debug flag.  This is normally not
	  used unless one is debugging the autoconfig program.

     -R   Tells the kernel to use the compiled in root device.
	  Normally the system uses the device from which it was
	  booted as the root/swap/pipe/dump device.

     Reboot normally places a shutdown record in the login
     accounting file /usr/adm/wtmp.  This is inhibited if the -q
     or -n options are present.  Note that the -f (fast reboot)
     and -n (don't sync) options are contradictory; the request
     for a fast reboot is ignored in this case.

     Halt and fastboot are synonymous with ``reboot -h'' and
     ``reboot -f'', respectively.

     Power fail and crash recovery: Normally, the system will
     reboot itself at power-up or after crashes if the contents
     of low memory are intact.	An automatic consistency check of
     the file systems will be performed, and unless this fails,
     the system will resume multi-user operations.

SEE ALSO
     autoconfig(8), sync(2), utmp(8), shutdown(8), syslogd(8)


Printed 11/24/99	  May 24, 1996				2