systemd-sysctl.service(8) — Linux manual page


SYSTEMD-S...L.SERVICE(8) systemd-sysctl.service SYSTEMD-S...L.SERVICE(8)

NAME         top

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

SYNOPSIS         top

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


DESCRIPTION         top

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

       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         top

           Only apply rules with the specified prefix.

           Added in version 230.

           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 "-"

           Added in version 252.

           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.

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

           Print a short version string and exit.

CREDENTIALS         top

       systemd-sysctl supports the service credentials logic as
       implemented by ImportCredential=/LoadCredential=/SetCredential=
       (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 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

EXAMPLES         top

       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

       See sysctl(8) for various ways to directly apply sysctl settings.

SEE ALSO         top

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

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨⟩.  If you have
       a bug report for this manual page, see
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-22.)  If you discover any rendering
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       (which is not part of the original manual page), send a mail to

systemd 255                                     SYSTEMD-S...L.SERVICE(8)

Pages that refer to this page: sysctl.d(5)systemd.directives(7)systemd.index(7)systemd-coredump(8)