Linux Runlevels Explained


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: https://www.liquidweb.com/kb/linux-runlevels-explained/https://www.liquidweb.com/kb/

For more information about this and other topics, visit us at https://www.liquidweb.com/kb/ or
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Video by: Alex Gorzen


Duration: 3:29
Publisher: Liquid Web
You can watch this video also at the source.


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