# phpman > info > SYSTEMD-SYSCTL.SERVICE

[SYSTEMD-SYSCTL.SERVICE(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-SYSCTL.SERVICE/8/markdown)   systemd-sysctl.service   [SYSTEMD-SYSCTL.SERVICE(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-SYSCTL.SERVICE/8/markdown)

NAME
       systemd-sysctl.service, systemd-sysctl - Configure kernel parameters at
       boot

SYNOPSIS
       /lib/systemd/systemd-sysctl [OPTIONS...] [CONFIGFILE...]

       systemd-sysctl.service

DESCRIPTION
       systemd-sysctl.service is an early boot service that configures
       [sysctl(8)](https://www.chedong.com/phpMan.php/man/sysctl/8/markdown) kernel parameters by invoking /lib/systemd/systemd-sysctl.

       When invoked with no arguments, /lib/systemd/systemd-sysctl applies all
       directives from configuration files listed in [sysctl.d(5)](https://www.chedong.com/phpMan.php/man/sysctl.d/5/markdown). If one or
       more filenames are passed on the command line, only the directives in
       these files are applied.

       In addition, --prefix= option may be used to limit which sysctl
       settings are applied.

       See [sysctl.d(5)](https://www.chedong.com/phpMan.php/man/sysctl.d/5/markdown) for information about the configuration of sysctl
       settings. After sysctl configuration is changed on disk, it must be
       written to the files in /proc/sys/ before it takes effect. It is
       possible to update specific settings, or simply to reload all
       configuration, see Examples below.

OPTIONS
       --prefix=
           Only apply rules with the specified prefix.

       --cat-config
           Copy the contents of config files to standard output. Before each
           file, the filename is printed as a comment.

       --no-pager
           Do not pipe output into a pager.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

EXAMPLES
       Example 1. Reset all sysctl settings

           systemctl restart systemd-sysctl

       Example 2. View coredump handler configuration

           # sysctl kernel.core_pattern
           kernel.core_pattern = |/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I

       Example 3. Update coredump handler configuration

           # /lib/systemd/systemd-sysctl --prefix kernel.core_pattern

       This searches all the directories listed in [sysctl.d(5)](https://www.chedong.com/phpMan.php/man/sysctl.d/5/markdown) for
       configuration files and writes /proc/sys/kernel/core_pattern.

       Example 4. Update coredump handler configuration according to a
       specific file

           # /lib/systemd/systemd-sysctl 50-coredump.conf

       This applies all the settings found in 50-coredump.conf. Either
       /etc/sysctl.d/50-coredump.conf, or /run/sysctl.d/50-coredump.conf, or
       /usr/lib/sysctl.d/50-coredump.conf will be used, in the order of
       preference.

       See [sysctl(8)](https://www.chedong.com/phpMan.php/man/sysctl/8/markdown) for various ways to directly apply sysctl settings.

SEE ALSO
       [systemd(1)](https://www.chedong.com/phpMan.php/man/systemd/1/markdown), [sysctl.d(5)](https://www.chedong.com/phpMan.php/man/sysctl.d/5/markdown), [sysctl(8)](https://www.chedong.com/phpMan.php/man/sysctl/8/markdown),

systemd 249                                          [SYSTEMD-SYSCTL.SERVICE(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-SYSCTL.SERVICE/8/markdown)