NAME

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

SYNOPSIS

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

       systemd-sysctl.service

DESCRIPTION

       systemd-sysctl.service is an early boot service that configures sysctl(8) kernel parameters by invoking
       /usr/lib/systemd/systemd-sysctl.

       When invoked with no arguments, /usr/lib/systemd/systemd-sysctl applies all directives from configuration
       files listed in sysctl.d(5). 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) 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.

           Added in version 230.

       --strict=
           Always return non-zero exit code on failure (including invalid sysctl variable name and insufficient
           permissions), unless the sysctl variable name is prefixed with a "-" character.

           Added in version 252.

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

       --tldr
           Copy the contents of config files to standard output. Only the "interesting" parts of the
           configuration files are printed, comments and empty lines are skipped. 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.

CREDENTIALS

       systemd-sysctl supports the service credentials logic as implemented by
       ImportCredential=/LoadCredential=/SetCredential= (see systemd.exec(5) for details). The following
       credentials are used when passed in:

       sysctl.extra
           The contents of this credential may contain additional lines to operate on. The credential contents
           should follow the same format as any other sysctl.d/ drop-in configuration file. If this credential
           is passed it is processed after all of the drop-in files read from the file system. The settings
           configured in the credential hence take precedence over those in the file system.

           Added in version 252.

       Note that by default the systemd-sysctl.service unit file is set up to inherit the "sysctl.extra"
       credential from the service manager.

EXAMPLES

       Example 1. Reset all sysctl settings

           systemctl restart systemd-sysctl

       Example 2. View coredump handler configuration

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

       Example 3. Update coredump handler configuration

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

       This searches all the directories listed in sysctl.d(5) for configuration files and writes
       /proc/sys/kernel/core_pattern.

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

           # /usr/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) for various ways to directly apply sysctl settings.

SEE ALSO

       systemd(1), sysctl.d(5), sysctl(8)