# systemd-sysctl.service

## 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.
    


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