Journalctl
From DikapediaV2
journalctl --no-pager --catalog --boot
Journalctl Disk Usage
Check Journalctl disk usage:
[ec2-user@ringroadlimo ~]$ journalctl --disk-usage Archived and active journals take up 1.0G on disk.
Journalctl will take up space over time in the directory /var/log/journalctl/*. It is safe to delete the contents but do not delete the directory.
You can control the size of this directory using this parameter in your /etc/systemd/journald.conf:
SystemMaxUse=50M
To clean logs after a period of time rather than when they reach a certain size, you can set the parameter MaxRetentionSec instead of SystemMaxUse. See man journald.conf for more details.
You can force a log rotation:
$ sudo systemctl kill --kill-who=main --signal=SIGUSR2 systemd-journald.service
NOTE: You might need to restart the logging service to force a log rotation, if the above signaling method does not do it. You can restart the service like so:
$ sudo systemctl restart systemd-journald.service