NAME

       sysctl.d - Configure kernel parameters at boot

SYNOPSIS

       /etc/sysctl.d/*.conf

       /run/sysctl.d/*.conf

       /usr/lib/sysctl.d/*.conf

DESCRIPTION

       At boot, systemd-sysctl.service(8) reads configuration files from the above directories to
       configure sysctl(8) kernel parameters.

CONFIGURATION FORMAT

       The configuration files contain a list of variable assignments, separated by newlines.
       Empty lines and lines whose first non-whitespace character is # or ; are ignored.

       Note that both / and . are accepted as label separators within sysctl variable names.
       kernel.domainname=foo and kernel/domainname=foo hence are entirely equivalent.

       Each configuration file shall be named in the style of program.conf. Files in /etc/
       override files with the same name in /usr/lib/ and /run/. Files in /run/ override files
       with the same name in /usr/lib/. Packages should install their configuration files in
       /usr/lib/. Files in /etc/ are reserved for the local administrator, who may use this logic
       to override the configuration files installed by vendor packages. All configuration files
       are sorted by their filename in alphabetical order, regardless in which of the directories
       they reside, to guarantee that a specific configuration file takes precedence over another
       file with an alphabetically later name, if both files contain the same variable setting.

       If the administrator wants to disable a configuration file supplied by the vendor the
       recommended way is to place a symlink to /dev/null in /etc/sysctl.d/ bearing the same file
       name.

EXAMPLE

       Example 1. /etc/sysctl.d/domain-name.conf example:

           # Set kernel YP domain name
           kernel.domainname=example.com

SEE ALSO

       systemd(1), systemd-sysctl.service(8), systemd-delta(1), sysctl(8), sysctl.conf(5)