JOURNALD.CONF(5)                journald.conf               JOURNALD.CONF(5)

NAME         top

       journald.conf, journald.conf.d - Journal service configuration files

SYNOPSIS         top





DESCRIPTION         top

       These files configure various parameters of the systemd journal
       service, systemd-journald.service(8).


       The default configuration is defined during compilation, so a
       configuration file is only needed when it is necessary to deviate
       from those defaults. By default, the configuration file in
       /etc/systemd/ contains commented out entries showing the defaults as
       a guide to the administrator. This file can be edited to create local

       When packages need to customize the configuration, they can install
       configuration snippets in /usr/lib/systemd/*.conf.d/. Files in /etc/
       are reserved for the local administrator, who may use this logic to
       override the configuration files installed by vendor packages. The
       main configuration file is read before any of the configuration
       directories, and has the lowest precedence; entries in a file in any
       configuration directory override entries in the single configuration
       file. Files in the *.conf.d/ configuration subdirectories are sorted
       by their filename in lexicographic order, regardless of which of the
       subdirectories they reside in. If multiple files specify the same
       option, the entry in the file with the lexicographically latest name
       takes precedence. It is recommended to prefix all filenames in those
       subdirectories with a two-digit number and a dash, to simplify the
       ordering of the files.

       To disable a configuration file supplied by the vendor, the
       recommended way is to place a symlink to /dev/null in the
       configuration directory in /etc/, with the same filename as the
       vendor configuration file.

OPTIONS         top

       All options are configured in the "[Journal]" section:

           Controls where to store journal data. One of "volatile",
           "persistent", "auto" and "none". If "volatile", journal log data
           will be stored only in memory, i.e. below the /run/log/journal
           hierarchy (which is created if needed). If "persistent", data
           will be stored preferably on disk, i.e. below the
           /var/log/journal hierarchy (which is created if needed), with a
           fallback to /run/log/journal (which is created if needed), during
           early boot and if the disk is not writable.  "auto" is similar to
           "persistent" but the directory /var/log/journal is not created if
           needed, so that its existence controls where log data goes.
           "none" turns off all storage, all log data received will be
           dropped. Forwarding to other targets, such as the console, the
           kernel log buffer, or a syslog socket will still work however.
           Defaults to "auto".

           Takes a boolean value. If enabled (the default), data objects
           that shall be stored in the journal and are larger than a certain
           threshold are compressed before they are written to the file

           Takes a boolean value. If enabled (the default), and a sealing
           key is available (as created by journalctl(1)'s --setup-keys
           command), Forward Secure Sealing (FSS) for all persistent journal
           files is enabled. FSS is based on Seekable Sequential Key
           Generators[1] by G. A. Marson and B. Poettering
           (doi:10.1007/978-3-642-40203-6_7) and may be used to protect
           journal files from unnoticed alteration.

           Controls whether to split up journal files per user, either "uid"
           or "none". Split journal files are primarily useful for access
           control: on UNIX/Linux access control is managed per file, and
           the journal daemon will assign users read access to their journal
           files. If "uid", all regular users will each get their own
           journal files, and system users will log to the system journal.
           If "none", journal files are not split up by user and all
           messages are instead stored in the single system journal. In this
           mode unprivileged users generally do not have access to their own
           log data. Note that splitting up journal files by user is only
           available for journals stored persistently. If journals are
           stored on volatile storage (see Storage= above), only a single
           journal file is used. Defaults to "uid".

       RateLimitIntervalSec=, RateLimitBurst=
           Configures the rate limiting that is applied to all messages
           generated on the system. If, in the time interval defined by
           RateLimitIntervalSec=, more messages than specified in
           RateLimitBurst= are logged by a service, all further messages
           within the interval are dropped until the interval is over. A
           message about the number of dropped messages is generated. This
           rate limiting is applied per-service, so that two services which
           log do not interfere with each other's limits. Defaults to 1000
           messages in 30s. The time specification for RateLimitIntervalSec=
           may be specified in the following units: "s", "min", "h", "ms",
           "us". To turn off any kind of rate limiting, set either value to

       SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, SystemMaxFiles=,
       RuntimeMaxUse=, RuntimeKeepFree=, RuntimeMaxFileSize=,
           Enforce size limits on the journal files stored. The options
           prefixed with "System" apply to the journal files when stored on
           a persistent file system, more specifically /var/log/journal. The
           options prefixed with "Runtime" apply to the journal files when
           stored on a volatile in-memory file system, more specifically
           /run/log/journal. The former is used only when /var is mounted,
           writable, and the directory /var/log/journal exists. Otherwise,
           only the latter applies. Note that this means that during early
           boot and if the administrator disabled persistent logging, only
           the latter options apply, while the former apply if persistent
           logging is enabled and the system is fully booted up.  journalctl
           and systemd-journald ignore all files with names not ending with
           ".journal" or ".journal~", so only such files, located in the
           appropriate directories, are taken into account when calculating
           current disk usage.

           SystemMaxUse= and RuntimeMaxUse= control how much disk space the
           journal may use up at most.  SystemKeepFree= and RuntimeKeepFree=
           control how much disk space systemd-journald shall leave free for
           other uses.  systemd-journald will respect both limits and use
           the smaller of the two values.

           The first pair defaults to 10% and the second to 15% of the size
           of the respective file system, but each value is capped to 4G. If
           the file system is nearly full and either SystemKeepFree= or
           RuntimeKeepFree= are violated when systemd-journald is started,
           the limit will be raised to the percentage that is actually free.
           This means that if there was enough free space before and journal
           files were created, and subsequently something else causes the
           file system to fill up, journald will stop using more space, but
           it will not be removing existing files to reduce the footprint
           again, either.

           SystemMaxFileSize= and RuntimeMaxFileSize= control how large
           individual journal files may grow at most. This influences the
           granularity in which disk space is made available through
           rotation, i.e. deletion of historic data. Defaults to one eighth
           of the values configured with SystemMaxUse= and RuntimeMaxUse=,
           so that usually seven rotated journal files are kept as history.

           Specify values in bytes or use K, M, G, T, P, E as units for the
           specified sizes (equal to 1024, 1024², ... bytes). Note that size
           limits are enforced synchronously when journal files are
           extended, and no explicit rotation step triggered by time is

           SystemMaxFiles= and RuntimeMaxFiles= control how many individual
           journal files to keep at most. Note that only archived files are
           deleted to reduce the number of files until this limit is
           reached; active files will stay around. This means that, in
           effect, there might still be more journal files around in total
           than this limit after a vacuuming operation is complete. This
           setting defaults to 100.

           The maximum time to store entries in a single journal file before
           rotating to the next one. Normally, time-based rotation should
           not be required as size-based rotation with options such as
           SystemMaxFileSize= should be sufficient to ensure that journal
           files do not grow without bounds. However, to ensure that not too
           much data is lost at once when old journal files are deleted, it
           might make sense to change this value from the default of one
           month. Set to 0 to turn off this feature. This setting takes time
           values which may be suffixed with the units "year", "month",
           "week", "day", "h" or "m" to override the default time unit of

           The maximum time to store journal entries. This controls whether
           journal files containing entries older then the specified time
           span are deleted. Normally, time-based deletion of old journal
           files should not be required as size-based deletion with options
           such as SystemMaxUse= should be sufficient to ensure that journal
           files do not grow without bounds. However, to enforce data
           retention policies, it might make sense to change this value from
           the default of 0 (which turns off this feature). This setting
           also takes time values which may be suffixed with the units
           "year", "month", "week", "day", "h" or " m" to override the
           default time unit of seconds.

           The timeout before synchronizing journal files to disk. After
           syncing, journal files are placed in the OFFLINE state. Note that
           syncing is unconditionally done immediately after a log message
           of priority CRIT, ALERT or EMERG has been logged. This setting
           hence applies only to messages of the levels ERR, WARNING,
           NOTICE, INFO, DEBUG. The default timeout is 5 minutes.

       ForwardToSyslog=, ForwardToKMsg=, ForwardToConsole=, ForwardToWall=
           Control whether log messages received by the journal daemon shall
           be forwarded to a traditional syslog daemon, to the kernel log
           buffer (kmsg), to the system console, or sent as wall messages to
           all logged-in users. These options take boolean arguments. If
           forwarding to syslog is enabled but nothing reads messages from
           the socket, forwarding to syslog has no effect. By default, only
           forwarding to wall is enabled. These settings may be overridden
           at boot time with the kernel command line options
           "systemd.journald.forward_to_console", and
           "systemd.journald.forward_to_wall". If the option name is
           specified without "=" and the following argument, true is
           assumed. Otherwise, the argument is parsed as a boolean. When
           forwarding to the console, the TTY to log to can be changed with
           TTYPath=, described below.

       MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=,
           Controls the maximum log level of messages that are stored on
           disk, forwarded to syslog, kmsg, the console or wall (if that is
           enabled, see above). As argument, takes one of "emerg", "alert",
           "crit", "err", "warning", "notice", "info", "debug", or integer
           values in the range of 0–7 (corresponding to the same levels).
           Messages equal or below the log level specified are
           stored/forwarded, messages above are dropped. Defaults to "debug"
           for MaxLevelStore= and MaxLevelSyslog=, to ensure that the all
           messages are written to disk and forwarded to syslog. Defaults to
           "notice" for MaxLevelKMsg=, "info" for MaxLevelConsole=, and
           "emerg" for MaxLevelWall=. These settings may be overridden at
           boot time with the kernel command line options

           Change the console TTY to use if ForwardToConsole=yes is used.
           Defaults to /dev/console.


       Journal events can be transferred to a different logging daemon in
       two different ways. With the first method, messages are immediately
       forwarded to a socket (/run/systemd/journal/syslog), where the
       traditional syslog daemon can read them. This method is controlled by
       the ForwardToSyslog= option. With a second method, a syslog daemon
       behaves like a normal journal client, and reads messages from the
       journal files, similarly to journalctl(1). With this, messages do not
       have to be read immediately, which allows a logging daemon which is
       only started late in boot to access all messages since the start of
       the system. In addition, full structured meta-data is available to
       it. This method of course is available only if the messages are
       stored in a journal file at all. So it will not work if Storage=none
       is set. It should be noted that usually the second method is used by
       syslog daemons, so the Storage= option, and not the ForwardToSyslog=
       option, is relevant for them.

SEE ALSO         top

       systemd(1), systemd-journald.service(8), journalctl(1),
       systemd.journal-fields(7), systemd-system.conf(5)

NOTES         top

        1. Seekable Sequential Key Generators

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
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systemd 234                                                 JOURNALD.CONF(5)

Pages that refer to this page: journalctl(1)coredump.conf(5)systemd.directives(7)systemd.index(7)systemd.journal-fields(7)systemd-journald.service(8)