# man > sysctl.conf(5)

[SYSCTL.CONF(5)](https://www.chedong.com/phpMan.php/man/SYSCTL.CONF/5/markdown)                              File Formats                              [SYSCTL.CONF(5)](https://www.chedong.com/phpMan.php/man/SYSCTL.CONF/5/markdown)



## NAME
       sysctl.conf - sysctl preload/configuration file

## DESCRIPTION
       **sysctl.conf**  is  a simple file containing sysctl values to be read in and set by **sysctl**.  The
       syntax is simply as follows:

              # comment
              ; comment

              token = value

       Note that blank lines are ignored, and whitespace before and after a token or  value  is  ig‐
       nored,  although  a value can contain whitespace within.  Lines which begin with a _#_ or _;_ are
       considered comments and ignored.

       If a line begins with a single -, any attempts to set the value that fail will be ignored.


## NOTES
       As the **/etc/sysctl.conf** file is used to override default  kernel  parameter  values,  only  a
       small  number  of  parameters  is  predefined  in  the  file.   Use _/sbin/sysctl_ _-a_ or follow
       [**sysctl**(8)](https://www.chedong.com/phpMan.php/man/sysctl/8/markdown) to list all possible parameters. The description of individual  parameters  can  be
       found in the kernel documentation.

## EXAMPLE
              # sysctl.conf sample
              #
                kernel.domainname = example.com
              ; this one has a space which will be written to the sysctl!
                kernel.modprobe = /sbin/mod probe

## FILES
       _/etc/sysctl.d/*.conf_
       _/run/sysctl.d/*.conf_
       _/usr/local/lib/sysctl.d/*.conf_
       _/usr/lib/sysctl.d/*.conf_
       _/lib/sysctl.d/*.conf_
       _/etc/sysctl.conf_

       The paths where **sysctl** preload files usually exist.  See also **sysctl** option _--system_.

## SEE ALSO
       [**sysctl**(8)](https://www.chedong.com/phpMan.php/man/sysctl/8/markdown)

## AUTHOR
       George Staikos ⟨<staikos@0wned.org>⟩

## REPORTING BUGS
       Please send bug reports to ⟨<procps@freelists.org>⟩



procps-ng                                    2020-06-04                               [SYSCTL.CONF(5)](https://www.chedong.com/phpMan.php/man/SYSCTL.CONF/5/markdown)