SYSCTL.D(5)							     sysctl.d							       SYSCTL.D(5)

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 lexicographic order, regardless of which of the directories they reside in. If
       multiple files specify the same variable name, the entry in the file with the lexicographically latest name will be applied. It is
       recommended to prefix all filenames with a two-digit number and a dash, to simplify the ordering of the files.

       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 filename.

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)

systemd 208															       SYSCTL.D(5)