Deleting Logs on Web-Server to free up diskspace

First rotate the logs, using the following command.

sudo /etc/cron.daily/logrotate

This should rotate the log files (so kern.log becomes kern.log.1); and you can then delete kern.log.1 etc to free up the disk space.

Then delete the old log files.

sudo find /var/log -type f -name "*.1" -delete

If thewre are too many old archived log files, delete them as well.

sudo find /var/log -type f -name "*.gz" -delete

Check Journalctl Logs

journalctl --disk-usage

Vacuum Logs older than a few days
journalctl --vacuum-time=2d

or Vacuum Logs keeping the minimum size

journalctl --vacuum-size=500M

You can control the size of this directory using this parameter in your /etc/systemd/journald.conf:

SystemMaxUse=50M