how to clear journal logs

Question

My server disk is full, and I cannot remove. How can we remove the journal logs and clear some space

Answer 1

Run 

journalctl --disk-usage

It will show the journal disk usage

then run

journalctl --vacuum-time=2d  -  Free logs older than 2 days

or

journalctl --vacuum-size=100M  -  keep only 100MB of logs