Configure RunLevel RHEL 7 or CentOS 7

Overview

The purpose of this document give insight into Linux Run levels configurations in RHEL 7 / CentOS 7 version.

Applies To

RHEL 7, CentOS 7

Run Levels

Systemd deals with run levels. As everything is represented by files in systemd, target files replace run levels.

System Commands Table

Options	Purpose
default	Enter system default mode
rescue	Enter system rescue mode
emergency	Enter system emergency mode
halt	Shut down and halt the system
poweroff	Shut down and power-off the system
reboot	Shut down and reboot the system
kexec	Shut down and reboot the system with kexec
exit	Request user instance exit
switch-root [ROOT] [INIT]	Change to a different root file system
suspend	Suspend the system
hibernate	Hibernate the system
hybrid-sleep	Hibernate and suspend the system

Switch to Maintenance Mode

To switch into maintenance mode, run the command;

systemctl rescue

Note: Other option is also available emergency target only available when set up in the kernel boot line (systemd.unit=emergency.target) and for critical situations.

Isolate

The purpose of “Isolate” attribute is to start one unit and stop all others.

Switch to multi-user (level 3) mode

To Switch into multi-user level, which is equivalent to pervious level 3

systemctl isolate multi-user.target

or:

systemctl isolate runlevel3.target

Switch to graphical (level 5) mode

To Switch into GUI mode, which is equivalent to the previous level 5

systemctl isolate graphical.target

or:

systemctl isolate runlevel5.target

Set default RunLevel to multi-user mode

systemctl set-default multi-user.target

Set default RunLevel to graphical mode

systemctl set-default graphical.target

Get current default RunLevel

To get / display the currently set default RunLevel.

systemctl get-default

Poweroff – Server

To poweroff the server run the command;

systemctl poweroff

Reboot – Server

To reboot the server with default runlevel, run the command;

systemctl reboot

Halt – Server

To halt the server, run the command;

systemctl halt

SlideShare Information

Guide to configure different Runlevels with screenshots is uploaded.