systemd-sysctl.service, systemd-sysctl — Configure kernel parameters at boot
/usr/lib/systemd/systemd-sysctl [OPTIONS...] [
systemd-sysctl.service is an early boot
service that configures
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.
--prefix= option may be used to limit which sysctl
settings are applied.
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.
Only apply rules with the specified prefix.
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.
Copy the contents of config files to standard output. Before each file, the filename is printed as a comment.
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.
Do not pipe output into a pager.
systemd-sysctl supports the service credentials logic as implemented by
(see systemd.exec(1) for
details). The following credentials are used when passed in:
The contents of this credential may contain additional lines to operate on. The
credential contents should follow the same format as any other
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
sysctl.extra" credential from the service manager.
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
for configuration files and writes
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
/usr/lib/sysctl.d/50-coredump.conf will be used, in the order
See sysctl(8) for various ways to directly apply sysctl settings.