I recently needed to free up disk space by removing old system logs, so I collected the command I used and other useful journalctl commands for future reference.
Disk usage & vacuum (remove old logs)
Show journal disk usage:
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sudo journalctl --disk-usageRemove archived journal files until total size is below X:
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sudo journalctl --vacuum-size=500MRemove archived journal files older than a time:
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sudo journalctl --vacuum-time=3dRemove archived journal files, keeping only the most recent N files:
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sudo journalctl --vacuum-files=3Maintenance & troubleshooting
Show journalctl help:
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journalctl --helpShow journald service status:
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systemctl status systemd-journaldCheck journal file integrity:
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sudo journalctl --verify