Linux Command learning Summary: reboot command, linuxreboot

Linux Command learning Summary: reboot command, linuxreboot

Command introduction:

This command is used to restart the Linux system. It is equivalent to the restart command in Windows.

Command syntax:

/Sbin/reboot [-n] [-w] [-d] [-f] [-I]

Or

Reboot [-n] [-w] [-d] [-f] [-I]

Command parameters:

Parameters	Long Parameter	Description
-D		Data is not written to the record file/var/tmp/wtmp during restart.
-F		Force reboot without calling the shutdown command.
-H		Put all hard disks in standby mode before system shutdown or poweroff
-I		Disable network settings and restart the system.
-N		Save the data and restart the system.
-P		When halting the system, do a poweroff. This is the default when halt is called as poweroff
-W		Only perform tests. If you do not restart the system, the system only writes the restarted data to the wtmp record file in the/var/log directory.
	-- Help	Show command online help

Example:

1: view the help information of the reboot command

[root@DB-Server ~]# reboot --help

usage: reboot [-n] [-w] [-d] [-f] [-h] [-i]

        -n: don't sync before halting the system

        -w: only write a wtmp reboot record and exit.

        -d: don't write a wtmp record.

        -f: force halt/reboot, don't call shutdown.

        -h: put harddisks in standby mode.

        -i: shut down all network interfaces.

[Root @ DB-Server ~] # Man reboot

[root@DB-Server ~]# man reboot

HALT (8) Linux System Administrator 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 poweroff the system.

If halt or reboot is called when the system is not in runlevel 0 or 6, in other words when it waits until running normally, shutdown will be invoked instead (

       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 Don't need to sync before reboot or halt. Note that the kernel and storage drivers may still sync.

-W Don't exactly actually reboot or halt but only write the wtmp record (in the/var/log/wtmp file ).

-D Don't need to write the wtmp record. The-n flag implies-d.

-F Force halt or reboot, don't have enough call shutdown (8 ).

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

       -h     Put all harddrives on the system in standby mode just before halt or poweroff.

       -p     When halting the system, do a poweroff. This is the default when halt is called as poweroff.

DIAGNOSTICS

If you have created e not the superuser, you will get the message must be superuser created? Users logged in locally on the console can call halt, reboot, and poweroff

       without supplying the root password, due to pam_console (8).

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 hasn has passed 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 harddisks in standby mode just before halt or poweroff. Right now this is only implemented for IDE drives. A side effect of putting

The drive in standby mode is that the write cache on the disk is flushed. This is important for IDE drives, since the kernel doesn has been flush the write-cache

       itself before poweroff.

       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), pam_console(8)

                                  Nov 6, 2001                          HALT(8)

(END) 

 

 2: Force reboot without calling the shutdown command

[Root @ DB-Server ~] # Reboot-f

3: Shut down the network settings and restart the system.

[root@DB-Server ~]# reboot -i

Broadcast message from root (pts/1) (Mon Jul 28 11:31:28 2014):

The system is going down for reboot NOW!

4: Save the data and restart the system.

[root@DB-Server ~]# reboot -n

Broadcast message from root (pts/1) (Mon Jul 28 11:33:57 2014):

The system is going down for reboot NOW!

5: Do not write data into the record file/var/tmp/wtmp upon restart

[root@DB-Server ~]# reboot -d

Broadcast message from root (pts/2) (Mon Jul 28 11:23:26 2014):

The system is going down for reboot NOW!

Linux reboot command can restart the system, but how can I write this script?

If you want to implement any function, restart the system to reboot it.

In Linux, what is the difference between Init and shuntdown and reboot?

Init is short for initial. It is the first process in linux, and all other processes are sub-processes. it is usually used to switch the running level, including the relevant machine and restart (a total of seven levels ).
Shutdown can be used to shut down and restart. reboot is also used to restart. They should all be achieved by calling init.