.TH REBOOT 8
.UC
.SH NAME
reboot \- UNIX bootstrapping procedures
.SH SYNOPSIS
.B /etc/reboot
[
.B \-n
] [
.B \-q
] [
.B \-f
] [
.B \-a
] [
.B \-h
] [
.B \-d
]
.SH DESCRIPTION
.PP
UNIX is started by placing it in memory
at location zero and transferring to zero.
Since the system is not reentrant,
it is necessary to read it in from disk or tape
each time it is to be bootstrapped.
.PP
.B Rebooting a running system.
When a UNIX is running and a reboot is desired,
.IR shutdown (8)
is normally used.
If there are no users then
.I /etc/reboot
can be used.
.I Reboot
normally causes the disks to be synced, and then a multi-user
reboot (as described below) is initiated.  This causes a system to be
booted and an automatic disk check to be performed.  If all this succeeds
without incident, the system is then brought up multiuser.
.PP
Options to
.I reboot
are:
.TP
.B \-\^n
option avoids the sync.
It is necessary to reboot without a sync after rebuilding
the root file system.
.TP
.B \-\^q
reboots quickly and ungracefully, without shutting down running
processes first.
.TP
.B \-\^f
fast boot, omitting the automatic file system consistency check.
.TP
.B \-\^a
.IR boot (8)
will ask for the name of the system to be booted,
rather than immediately booting the default system.
.TP
.B \-\^h
halt the system rather than rebooting.
.TP
.B \-\^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.
.PP
.B "Power fail and crash recovery."
The system will normally reboot itself after crashes
and power failures (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 multiuser operations.
.PP
.B Cold starts.
These are processor dependent.
See
.IR boot (8).
.SH FILES
.ta 2.5i
/unix	system code
.br
/usr/src/sys/mdec/xxboot	block 0 bootstrap for boot device xx
.br
/boot	system bootstrap, on boot disk file system
.br
/etc/init
.br
/etc/rc	script to check file systems and bring the system up
.SH "SEE ALSO"
crash(8), fsck(8), init(8), rc(8), shutdown(8)