systemd systemd-sysctl.service 8 systemd-sysctl.service systemd-sysctl Configure kernel parameters at boot /usr/lib/systemd/systemd-sysctl OPTIONS CONFIGFILE systemd-sysctl.service systemd-sysctl.service is an early boot service that configures sysctl8 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.d5. 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.d5 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. --prefix= Only apply rules with the specified prefix. --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. systemd-sysctl supports the service credentials logic as implemented by ImportCredential=/LoadCredential=/SetCredential= (see systemd.exec5 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. Note that by default the systemd-sysctl.service unit file is set up to inherit the sysctl.extra credential from the service manager. systemctl restart systemd-sysctl # sysctl kernel.core_pattern kernel.core_pattern = |/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I # /usr/lib/systemd/systemd-sysctl --prefix kernel.core_pattern This searches all the directories listed in sysctl.d5 for configuration files and writes /proc/sys/kernel/core_pattern. # /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 sysctl8 for various ways to directly apply sysctl settings. systemd1 sysctl.d5 sysctl8