# Analyzing systemd Logs with journalctl The `journalctl` tool queries the contents of the `systemd` journal. The following command displays the messages that `systemd` generated the last time the machine started: journalctl -b The following command reveals the messages for the systemd service unit specified by the `-u` option: journalctl -u auditd In the above example, `auditd` is the system service unit. For more information, see the `journalctl` man page by running the following command on Photon OS: ``` man journalctl ```