SYSCTL.CONF(5)		       File Formats Manual		  SYSCTL.CONF(5)

NAME
     sysctl.conf - Linux kernel configuration parameters

DESCRIPTION
     sysctl.conf  is a set of configuration files that contain Linux kernel con-
     figuration parameters to be read and set by sysctl(8).

     This man page describes the configuration files for procps sysctl.	 If  you
     are  using	 systemd-sysctl(8),  refer to sysctl.d(5) and note that it won't
     use the file /etc/sysctl.conf.

   Configuration Format
     Each line of a file read by procps sysctl describes a kernel  parameter  in
     the following format.

	    token = value

     There  is	no need to use quotation marks for value, even if the value is a
     list of items.

     Blank lines and lines that start with "#" or ";" are ignored.

     If a line begins with a single "-", a failing attempt to set the  value  is
     ignored.

FILES
     procps sysctl, when run with the --system option, reads files from directo-
     ries in the order shown below.

	    /etc/sysctl.d/*.conf
	    /run/sysctl.d/*.conf
	    /usr/local/lib/sysctl.d/*.conf
	    /usr/lib/sysctl.d/*.conf
	    /lib/sysctl.d/*.conf

     Finally,  procps  sysctl  reads /etc/sysctl.conf.	This file is not used by
     systemd-sysctl, which means that some kernel parameters are not set depend-
     ing on the implementation of sysctl that is installed.

BUGS
     The maximum supported length of value is 4096 characters due to  a	 limita-
     tion on /proc entry length in the Linux kernel.

EXAMPLES
     #
     #
     kernel.domainname = example.com
     ; A value containing a space is written to the sysctl.
     kernel.modprobe = /sbin/mod probe
     # A list of items for the value
     net.ipv4.ip_local_reserved_ports=8080,9148

SEE ALSO
     sysctl.d(5), sysctl(8), systemd-sysctl(8)

procps-ng			   2025-05-29			  SYSCTL.CONF(5)