journald.conf(5) — Linux manual page


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

NAME         top

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

SYNOPSIS         top


DESCRIPTION         top

       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 and associated drop-ins 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.


       The default configuration is set during compilation, so
       configuration is only needed when it is necessary to deviate from
       those defaults. The main configuration file is loaded from one of
       the listed directories in order of priority, only the first file
       found is used: /etc/systemd/, /run/systemd/,
       /usr/local/lib/systemd/ [1], /usr/lib/systemd/. The vendor
       version of the file contains commented out entries showing the
       defaults as a guide to the administrator. Local overrides can
       also be created by creating drop-ins, as described below. The
       main configuration file can also be edited for this purpose (or a
       copy in /etc/ if it's shipped under /usr/), however 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 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. This also defines a
       concept of drop-in priorities to allow OS vendors to ship
       drop-ins within a specific range lower than the range used by
       users. This should lower the risk of package drop-ins overriding
       accidentally drop-ins defined by users. It is recommended to use
       the range 10-40 for drop-ins in /usr/ and the range 60-90 for
       drop-ins in /etc/ and /run/, to make sure that local and
       transient drop-ins take priority over drop-ins shipped by the OS

       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" 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 journald will initially use volatile storage, until
           a call to journalctl --flush (or sending SIGUSR1 to journald)
           will cause it to switch to persistent logging (under the
           conditions mentioned above). This is done automatically on
           boot via "systemd-journal-flush.service".

           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.

           When journal namespacing (see LogNamespace= in
           systemd.exec(5)) is used, setting Storage= to "volatile" or
           "auto" will not have an effect on the creation of the
           per-namespace logs directory in /var/log/journal/, as the
           systemd-journald@.service service file by default carries
           LogsDirectory=. To turn that off, add a unit file drop-in
           file that sets LogsDirectory= to an empty string.

           Note that per-user journal files are not supported unless
           persistent storage is enabled, thus making journalctl --user

           The storage to use can also be specified via the
           "" credential. Values configured via
           configuration files take priority over values configured via
           the credential.

           Added in version 186.

           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 G can be used to specify
           larger units.

           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[2] 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.

           Added in version 189.

           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 Users,
           Groups, UIDs and GIDs on systemd systems[3] 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".

           Added in version 190.

       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 the base 2

           Table 1. Example RateLimitBurst= rate modifications by the
           available disk space
           │ Available Disk Space Burst Multiplier │
           │ <= 1MB               │ 1                │
           │ <= 16MB              │ 2                │
           │ <= 256MB             │ 3                │
           │ <= 4GB               │ 4                │
           │ <= 64GB              │ 5                │
           │ <= 1TB               │ 6                │

           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=,
       SystemMaxFiles=, RuntimeMaxUse=, RuntimeKeepFree=,
       RuntimeMaxFileSize=, 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
           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. 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
           SystemMaxUse= 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= capped to 128M, so that usually seven rotated
           journal files are kept as history. If the journal compact
           mode is enabled (enabled by default), the maximum file size
           is capped to 4G.

           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 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.

           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

           Added in version 195.

           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 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.

           Added in version 195.

           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

           Added in version 199.

       ForwardToSyslog=, ForwardToKMsg=, ForwardToConsole=,
       ForwardToWall=, ForwardToSocket=
           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, sent as wall
           messages to all logged-in users or sent over a socket. These
           options take boolean arguments except for "ForwardToSocket="
           which takes an address instead. 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.

           The socket forwarding address can be specified with the
           credential "journal.forward_to_socket". The following socket
           types are supported:

           AF_INET (e.g. ""), AF_INET6 (e.g.
           "[2001:db8::ff00:42:8329]:4444"), AF_UNIX (e.g.
           "/run/host/journal/socket"), AF_VSOCK (e.g. "vsock:2:1234")

           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

           When forwarding over a socket the Journal Export Format[4] is
           used when sending over the wire. Notably this includes the
           metadata field __REALTIME_TIMESTAMP so that
           systemd-journal-remote (see
           systemd-journal-remote.service(8)) can be used to receive the
           forwarded journal entries.

           Note: Forwarding is performed synchronously within journald,
           and may significantly affect its performance. This is
           particularly relevant when using ForwardToConsole=yes in
           cloud environments, where the console is often a slow,
           virtual serial port. Since journald is implemented as a
           conventional single-process daemon, forwarding to a
           completely hung console will block journald. This can have a
           cascading effect resulting in any services synchronously
           logging to the blocked journal also becoming blocked. Unless
           actively debugging/developing something, it's generally
           preferable to setup a journalctl --follow style service
           redirected to the console, instead of ForwardToConsole=yes,
           for production use.

           Note: Using ForwardToSocket= over IPv4/IPv6 links can be very
           slow due to the synchronous nature of the sockets. Take care
           to ensure your link is a low-latency local link if possible.
           Typically IP networking is not available everywhere journald
           runs, e.g. in the initrd during boot. Consider using
           AF_VSOCK/AF_UNIX sockets for this if possible.

       MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=,
       MaxLevelWall=, MaxLevelSocket=
           Controls the maximum log level of messages that are stored in
           the journal, forwarded to syslog, kmsg, the console, the
           wall, or a socket (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=, MaxLevelSyslog= and MaxLevelSocket=, to
           ensure that the all messages are stored in the journal,
           forwarded to syslog and the socket if one exists. 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

           Added in version 185.

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

           Added in version 235.

           Takes a boolean value. If enabled systemd-journald 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. This means if another tool
           turns on auditing even if systemd-journald left it off, it
           will still collect the generated messages. Defaults to on.

           Note that this option does not control whether
           systemd-journald collects generated audit records, it just
           controls whether it tells the kernel to generate them. If you
           need to prevent systemd-journald from collecting the
           generated messages, the socket unit
           "systemd-journald-audit.socket" can be disabled and in this
           case this setting is without effect.

           Added in version 246.

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

           Added in version 185.

           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 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.

           Added in version 235.


       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. 💣💥🧨💥💥💣 Please note that those configuration files must
           be available at all times. If /usr/local/ is a separate
           partition, it may not be available during early boot, and
           must not be used for configuration.

        2. Seekable Sequential Key Generators

        3. Users, Groups, UIDs and GIDs on systemd systems

        4. Journal Export Format

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 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-06-13.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

systemd 257~devel                                       JOURNALD.CONF(5)

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