15.0 journalctl: Query the systemd Journal

When systemd replaced traditional init scripts in SUSE Linux Enterprise 12 (see Section 13.0, The systemd Daemon), it introduced its own logging system called journal. There is no need to run a syslog based service anymore, as all system events are written in the journal.

The journal itself is a system service managed by systemd. Its full name is systemd-journald.service. It collects and stores logging data by maintaining structured indexed journals based on logging information received from the kernel, user processes, standard input, and system service errors. The systemd-journald service is on by default:

# systemctl status systemd-journald
systemd-journald.service - Journal Service
   Loaded: loaded (/usr/lib/systemd/system/systemd-journald.service; static)
   Active: active (running) since Mon 2014-05-26 08:36:59 EDT; 3 days ago
     Docs: man:systemd-journald.service(8)
 Main PID: 413 (systemd-journal)
   Status: "Processing requests..."
   CGroup: /system.slice/systemd-journald.service
           └─413 /usr/lib/systemd/systemd-journald