1SYSTEMD-SYSCTL.SERVICE(8) systemd-sysctl.service SYSTEMD-SYSCTL.SERVICE(8)
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6 systemd-sysctl.service, systemd-sysctl - Configure kernel parameters at
7 boot
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10 /usr/lib/systemd/systemd-sysctl [OPTIONS...] [CONFIGFILE...]
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12 systemd-sysctl.service
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15 systemd-sysctl.service is an early boot service that configures
16 sysctl(8) kernel parameters by invoking
17 /usr/lib/systemd/systemd-sysctl.
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19 When invoked with no arguments, /usr/lib/systemd/systemd-sysctl applies
20 all directives from configuration files listed in sysctl.d(5). If one
21 or more filenames are passed on the command line, only the directives
22 in these files are applied.
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24 In addition, --prefix= option may be used to limit which sysctl
25 settings are applied.
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27 See sysctl.d(5) for information about the configuration of sysctl
28 settings. After sysctl configuration is changed on disk, it must be
29 written to the files in /proc/sys/ before it takes effect. It is
30 possible to update specific settings, or simply to reload all
31 configuration, see Examples below.
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34 --prefix=
35 Only apply rules with the specified prefix.
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37 --strict=
38 Always return non-zero exit code on failure (including invalid
39 sysctl variable name and insufficient permissions), unless the
40 sysctl variable name is prefixed with a "-" character.
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42 --cat-config
43 Copy the contents of config files to standard output. Before each
44 file, the filename is printed as a comment.
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46 --no-pager
47 Do not pipe output into a pager.
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49 -h, --help
50 Print a short help text and exit.
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52 --version
53 Print a short version string and exit.
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56 systemd-sysctl supports the service credentials logic as implemented by
57 LoadCredential=/SetCredential= (see systemd.exec(1) for details). The
58 following credentials are used when passed in:
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60 "sysctl.extra"
61 The contents of this credential may contain additional lines to
62 operate on. The credential contents should follow the same format
63 as any other sysctl.d/ drop-in configuration file. If this
64 credential is passed it is processed after all of the drop-in files
65 read from the file system. The settings configured in the
66 credential hence take precedence over those in the file system.
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68 Note that by default the systemd-sysctl.service unit file is set up to
69 inherit the "sysctl.extra" credential from the service manager.
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72 Example 1. Reset all sysctl settings
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74 systemctl restart systemd-sysctl
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76 Example 2. View coredump handler configuration
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78 # sysctl kernel.core_pattern
79 kernel.core_pattern = |/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I
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81 Example 3. Update coredump handler configuration
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83 # /usr/lib/systemd/systemd-sysctl --prefix kernel.core_pattern
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85 This searches all the directories listed in sysctl.d(5) for
86 configuration files and writes /proc/sys/kernel/core_pattern.
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88 Example 4. Update coredump handler configuration according to a
89 specific file
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91 # /usr/lib/systemd/systemd-sysctl 50-coredump.conf
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93 This applies all the settings found in 50-coredump.conf. Either
94 /etc/sysctl.d/50-coredump.conf, or /run/sysctl.d/50-coredump.conf, or
95 /usr/lib/sysctl.d/50-coredump.conf will be used, in the order of
96 preference.
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98 See sysctl(8) for various ways to directly apply sysctl settings.
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101 systemd(1), sysctl.d(5), sysctl(8)
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105systemd 253 SYSTEMD-SYSCTL.SERVICE(8)