sysctl.conf - sysctl preload/configuration file
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 ignored, 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.
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) to list all possible parameters. The description of individual parameters can be found in the kernel documentation.
# sysctl.conf sample # kernel.domainname = example.com ; this one has a space which will be written to the sysctl! kernel.modprobe = /sbin/mod probe
/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.