“Created slice user-0.slice.” and “Starting Session 6642 of user root.” in /var/log/messages
I found the following entries in my /var/log/messages file
Feb 21 03:50:01 vm1 systemd: Created slice user-0.slice. Feb 21 03:50:01 vm1 systemd: Starting Session 6642 of user root. Feb 21 03:50:01 vm1 systemd: Started Session 6642 of user root.
These are low priority “info”-level messages related to session and resource management. I turned them off with the command:
systemd-analyze set-log-level notice
Or- update to Centos 7.2 or higher
See: https://bugs.centos.org/view.php?id=8957