How to reload sysctl.conf

Linux provides a sysctl interface for checking and modifying kernel parameters which are listed under /proc/sys directory. You can persistently set or change those kernel parameters via /etc/sysctl.conf.

If you have modified /etc/sysctl.conf, and want to activate the change in the kernel without rebooting, you need to do the following.

On FreeBSD:

$ sudo /etc/rc.d/sysctl reload

On Linux:

$ sudo sysctl -p /etc/sysctl.conf

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Dan Nanni is the founder and also a regular contributor of He is a Linux/FOSS enthusiast who loves to get his hands dirty with his Linux box. He likes to procrastinate when he is supposed to be busy and productive. When he is otherwise free, he likes to watch movies and shop for the coolest gadgets.

One thought on “How to reload sysctl.conf

  1. The problem with sysctl is to make sure that you have enough permissions when you are rebooting.
    I had some trouble even doing that from root, long story short that I ran out of ports and I wanted to change it.

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