SYSTEMD-JOURNALD.SERVICE(8)          systemd-journald.service         SYSTEMD-JOURNALD.SERVICE(8)



NAME
       systemd-journald.service, systemd-journald.socket, systemd-journald-dev-log.socket,
       systemd-journald - Journal service

SYNOPSIS
       systemd-journald.service

       systemd-journald.socket

       systemd-journald-dev-log.socket

       /lib/systemd/systemd-journald

DESCRIPTION
       systemd-journald is a system service that collects and stores logging data. It creates and
       maintains structured, indexed journals based on logging information that is received from
       the kernel, from user processes via the libc syslog(3) call, from standard input and
       standard error of system services or via its native API. It will implicitly collect
       numerous metadata fields for each log messages in a secure and unfakeable way. See
       systemd.journal-fields(7) for more information about the collected metadata.

       Log data collected by the journal is primarily text-based but can also include binary data
       where necessary. All objects stored in the journal can be up to 2^64-1 bytes in size.

       By default, the journal stores log data in /run/log/journal/. Since /run/ is volatile, log
       data is lost at reboot. To make the data persistent, it is sufficient to create
       /var/log/journal/ where systemd-journald will then store the data.

       systemd-journald will forward all received log messages to the AF_UNIXSOCK_DGRAM socket
       /run/systemd/journal/syslog, if it exists, which may be used by Unix syslog daemons to
       process the data further.

       See journald.conf(5) for information about the configuration of this service.

SIGNALS
       SIGUSR1
           Request that journal data from /run/ is flushed to /var/ in order to make it
           persistent (if this is enabled). This must be used after /var/ is mounted, as
           otherwise log data from /run is never flushed to /var regardless of the configuration.

       SIGUSR2
           Request immediate rotation of the journal files.

KERNEL COMMAND LINE
       A few configuration parameters from journald.conf may be overridden on the kernel command
       line:

       systemd.journald.forward_to_syslog=, systemd.journald.forward_to_kmsg=,
       systemd.journald.forward_to_console=, systemd.journald.forward_to_wall=
           Enables/disables forwarding of collected log messages to syslog, the kernel log
           buffer, the system console or wall.

           See journald.conf(5) for information about these settings.

ACCESS CONTROL
       Journal files are, by default, owned and readable by the "systemd-journal" system group
       but are not writable. Adding a user to this group thus enables her/him to read the journal
       files.

       By default, each logged in user will get her/his own set of journal files in
       /var/log/journal/. These files will not be owned by the user, however, in order to avoid
       that the user can write to them directly. Instead, file system ACLs are used to ensure the
       user gets read access only.

       Additional users and groups may be granted access to journal files via file system access
       control lists (ACL). Distributions and administrators may choose to grant read access to
       all members of the "wheel" and "adm" system groups with a command such as the following:

           # setfacl -Rnm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/

       Note that this command will update the ACLs both for existing journal files and for future
       journal files created in the /var/log/journal/ directory.

FILES
       /etc/systemd/journald.conf
           Configure systemd-journald behaviour. See journald.conf(5).

       /run/log/journal/machine-id/*.journal, /run/log/journal/machine-id/*.journal~,
       /var/log/journal/machine-id/*.journal, /var/log/journal/machine-id/*.journal~
           systemd-journald writes entries to files in /run/log/journal/machine-id/ or
           /var/log/journal/machine-id/ with the ".journal" suffix. If the daemon is stopped
           uncleanly, or if the files are found to be corrupted, they are renamed using the
           ".journal~" suffix, and systemd-journald starts writing to a new file.  /run is used
           when /var/log/journal is not available, or when Storage=volatile is set in the
           journald.conf(5) configuration file.

SEE ALSO
       systemd(1), journalctl(1), journald.conf(5), systemd.journal-fields(7), sd-journal(3),
       systemd-coredump(8), setfacl(1), pydoc systemd.journal.



systemd 215                                                           SYSTEMD-JOURNALD.SERVICE(8)