Linux Runlevels Explained

October 2, 2019 Liquid Web

In this video, we will explain what a runlevel is, what each Linux runlevel is for, and an example of how to manage a service using a runlevel. 

Commands used:
Level 0 is for shutting down the system. Nothing runs and the system just halts all functions.

Level 1 is Single-User Mode, which means only root has access to the system, the network access, and other non-vital services won't run. Generally, this is more of a recovery mode than something that would be used regularly. It can be used to reset the root password if you get locked out.

Level 2 is Multi-User Mode, so basically the same as level 1, but it allows other users to log in as well.

Level 3 is Multi-User Mode with Networking. This is how most servers run as it allows external communication but doesn't use a graphical user interface.

Level 4 is Undefined. It's for allowing custom user runlevels to be configured if there is a specific configuration that needs to be used regularly.

Level 5 Is X11 Mode, which means it has everything level 3 has plus the GUI. So Linux desktops and home users would generally boot into this mode by default.

Level 6 is for rebooting the system. So like level 0 you wouldn't boot into this mode, but the system will switch to this mode when the reboot process in initiated.

chkconfig --list 
chkconfig memcached off
chkconfig memcached on

The related article for this article can be found here:

For more information about this and other topics, visit us at or
For more information on VPS visit: to learn more about our current specials!

Video by: Alex Gorzen

About the Author

Liquid Web

Liquid Web powers online content, commerce, and potential for SMB entrepreneurs and the designers, developers and digital agencies who create for them. Sign up for our <a href="">newsletter</a> to stay up to date with our latest content.

More Content by Liquid Web
Previous Video
How To Install and Configure SNMP on CentOS
How To Install and Configure SNMP on CentOS

In this video, we demonstrate to you how to do setup SNMP or Simple Network Management Protocol. SNMP is wi...

Next Video
Installing Tomcat 9 on Windows
Installing Tomcat 9 on Windows

In this video, we outline how to install Tomcat 9 on Windows. We define what Tomcat is, the prerequisites n...

Learn What Qualities to Look for in Your Next Host in Our New Guide!

Download Now