Installing the recent linux version seems to come with a default setting of flooding the /var/log/messages with entirely annoying duplicitous messages like:
systemd: Created slice user-0.slice.
systemd: Starting Session 1013 of user root.
systemd: Started Session 1013 of user root.
systemd: Created slice user-0.slice.
systemd: Starting Session 1014 of user root.
systemd: Started Session 1014 of user root.
Here is how I got rid of these:
vi /etc/systemd/system.conf
And then uncomment LogLevel and make it:
LogLevel=notice
Then:
systemctl restart rsyslog
systemd-analyze set-log-level notice