JOURNALD.CONF(5)                                 JOURNALD.CONF(5)

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

     SYNOPSIS
          /etc/systemd/journald.conf

          /etc/systemd/journald.conf.d/*.conf

          /run/systemd/journald.conf.d/*.conf

          /usr/lib/systemd/journald.conf.d/*.conf

          /etc/systemd/journald@NAMESPACE.conf

     DESCRIPTION
          These files configure various parameters of the systemd
          journal service, systemd-journald.service(8). See
          systemd.syntax(7) for a general description of the syntax.

          The systemd-journald instance managing the default namespace
          is configured by /etc/systemd/journald.conf and associated
          drop-ins. Instances managing other namespaces read
          /etc/systemd/journald@NAMESPACE.conf with the namespace
          identifier filled in. This allows each namespace to carry a
          distinct configuration. See systemd-journald.service(8) for
          details about journal namespaces.

     CONFIGURATION DIRECTORIES AND PRECEDENCE
          The default configuration is set during compilation, so
          configuration is only needed when it is necessary to deviate
          from those defaults. Initially, the main configuration file
          in /etc/systemd/ contains commented out entries showing the
          defaults as a guide to the administrator. Local overrides
          can be created by editing this file or by creating drop-ins,
          as described below. Using drop-ins for local configuration
          is recommended over modifications to the main configuration
          file.

          In addition to the "main" configuration file, drop-in
          configuration snippets are read from
          /usr/lib/systemd/*.conf.d/,
          /usr/local/lib/systemd/*.conf.d/, and
          /etc/systemd/*.conf.d/. Those drop-ins have higher
          precedence and override the main configuration file. Files
          in the *.conf.d/ configuration subdirectories are sorted by
          their filename in lexicographic order, regardless of in
          which of the subdirectories they reside. When multiple files
          specify the same option, for options which accept just a
          single value, the entry in the file sorted last takes

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          precedence, and for options which accept a list of values,
          entries are collected as they occur in the sorted files.

          When packages need to customize the configuration, they can
          install drop-ins under /usr/. Files in /etc/ are reserved
          for the local administrator, who may use this logic to
          override the configuration files installed by vendor
          packages. Drop-ins have to be used to override package
          drop-ins, since the main configuration file has lower
          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
          All options are configured in the [Journal] section:

          Storage=
              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" behaves like
              "persistent" if the /var/log/journal directory exists,
              and "volatile" otherwise (the existence of the directory
              controls the storage mode).  "none" turns off all
              storage, all log data received will be dropped (but
              forwarding to other targets, such as the console, the
              kernel log buffer, or a syslog socket will still work).
              Defaults to "auto" in the default journal namespace, and
              "persistent" in all others.

              Note that when this option is changed to "volatile",
              existing persistent data is not removed. In the other
              direction, journalctl(1) with the --flush option may be
              used to move volatile data to persistent storage.

          Compress=
              Can take a boolean value. If enabled (the default), data
              objects that shall be stored in the journal and are
              larger than the default threshold of 512 bytes are
              compressed before they are written to the file system.
              It can also be set to a number of bytes to specify the
              compression threshold directly. Suffixes like K, M, and

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              G can be used to specify larger units.

          Seal=
              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
              m[blue]Seekable Sequential Key Generatorsm[][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.

          SplitMode=
              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 (with UID outside the
              range of system users, dynamic service users, and the
              nobody user) will each get their own journal files, and
              system users will log to the system journal. See
              m[blue]Users, Groups, UIDs and GIDs on systemd
              systemsm[][2] for more details about UID ranges. 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 10000 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
              0.

              Note that the effective rate limit is multiplied by a
              factor derived from the available free disk space for
              the journal. Currently, this factor is calculated using

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              the base 2 logarithm.

              Table 1. Example RateLimitBurst= rate modifications by
              the allbox tab(:); lB lB.  T{ Available Disk Space T}:T{
              Burst Multiplier T} l l l l l l l l l l l l.  T{ <= 1MB
              T}:T{ 1 T} T{ <= 16MB T}:T{ 2 T} T{ <= 256MB T}:T{ 3 T}
              T{ <= 4GB T}:T{ 4 T} T{ <= 64GB T}:T{ 5 T} T{ <= 1TB
              T}:T{ 6 T}

              If a service provides rate limits for itself through
              LogRateLimitIntervalSec= and/or LogRateLimitBurst= in
              systemd.exec(5), those values will override the settings
              specified here.

          SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, System-
          MaxFiles=, RuntimeMaxUse=, RuntimeKeepFree=, RuntimeMaxFile-
          Size=, RuntimeMaxFiles=
              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 administra-
              tor 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

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              existing files to reduce the footprint again, either.
              Also note that only archived files are deleted to reduce
              the space occupied by journal files. This means that, in
              effect, there might still be more space used than Sys-
              temMaxUse= or RuntimeMaxUse= limit after a vacuuming
              operation is complete.

              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, 1024S2, ...
              bytes). Note that size limits are enforced synchronously
              when journal files are extended, and no explicit rota-
              tion step triggered by time is needed.

              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.

          MaxFileSec=
              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 seconds.

          MaxRetentionSec=
              The maximum time to store journal entries. This controls
              whether journal files containing entries older than 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

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              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.

          SyncIntervalSec=
              The timeout before synchronizing journal files to disk.
              After syncing, journal files are placed in the OFFLINE
              state. Note that syncing is unconditionally done immedi-
              ately 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=, For-
          wardToWall=
              Control whether log messages received by the journal
              daemon shall be forwarded to a traditional syslog dae-
              mon, to the kernel log buffer (kmsg), to the system con-
              sole, 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 syslog and wall is enabled. These
              settings may be overridden at boot time with the kernel
              command line options
              "systemd.journald.forward_to_syslog",
              "systemd.journald.forward_to_kmsg",
              "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.

              When forwarding to the kernel log buffer (kmsg), make
              sure to select a suitably large size for the log buffer,
              for example by adding "log_buf_len=8M" to the kernel
              command line.  systemd will automatically disable
              kernel's rate-limiting applied to userspace processes
              (equivalent to setting "printk.devkmsg=on").

          MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelCon-
          sole=, MaxLevelWall=
              Controls the maximum log level of messages that are
              stored in the journal, 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

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              in the range of 0en7 (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 stored in the journal
              and forwarded to syslog. Defaults to "notice" for Max-
              LevelKMsg=, "info" for MaxLevelConsole=, and "emerg" for
              MaxLevelWall=. These settings may be overridden at boot
              time with the kernel command line options
              "systemd.journald.max_level_store=",
              "systemd.journald.max_level_syslog=",
              "systemd.journald.max_level_kmsg=",
              "systemd.journald.max_level_console=",
              "systemd.journald.max_level_wall=".

          ReadKMsg=
              Takes a boolean value. If enabled systemd-journal pro-
              cesses /dev/kmsg messages generated by the kernel. In
              the default journal namespace this option is enabled by
              default, it is disabled in all others.

          Audit=
              Takes a boolean value. If enabled systemd-journal will
              turn on kernel auditing on start-up. If disabled it will
              turn it off. If unset it will neither enable nor disable
              it, leaving the previous state unchanged. Note that this
              option does not control whether systemd-journald col-
              lects generated audit records, it just controls whether
              it tells the kernel to generate them. This means if
              another tool turns on auditing even if systemd-journald
              left it off, it will still collect the generated mes-
              sages. Defaults to off.

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

          LineMax=
              The maximum line length to permit when converting stream
              logs into record logs. When a systemd unit's standard
              output/error are connected to the journal via a stream
              socket, the data read is split into individual log
              records at newline ("\n", ASCII 10) and NUL characters.
              If no such delimiter is read for the specified number of
              bytes a hard log record boundary is artificially
              inserted, breaking up overly long lines into multiple
              log records. Selecting overly large values increases the
              possible memory usage of the Journal daemon for each
              stream client, as in the worst case the journal daemon
              needs to buffer the specified number of bytes in memory
              before it can flush a new log record to disk. Also note
              that permitting overly large line maximum line lengths

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              affects compatibility with traditional log protocols as
              log records might not fit anymore into a single AF_UNIX
              or AF_INET datagram. Takes a size in bytes. If the value
              is suffixed with K, M, G or T, the specified size is
              parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes
              (with the base 1024), respectively. Defaults to 48K,
              which is relatively large but still small enough so that
              log records likely fit into network datagrams along with
              extra room for metadata. Note that values below 79 are
              not accepted and will be bumped to 79.

     FORWARDING TO TRADITIONAL SYSLOG DAEMONS
          Journal events can be transferred to a different logging
          daemon in two different ways. With the first method, mes-
          sages are immediately forwarded to a socket
          (/run/systemd/journal/syslog), where the traditional syslog
          daemon can read them. This method is controlled by the For-
          wardToSyslog= 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
          systemd(1), systemd-journald.service(8), journalctl(1),
          systemd.journal-fields(7), systemd-system.conf(5)

     NOTES
           1. Seekable Sequential Key Generators
              https://eprint.iacr.org/2013/397

           2. Users, Groups, UIDs and GIDs on systemd systems
              https://systemd.io/UIDS-GIDS

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