I have a new CentOS 7 installation, and noticed that my /var/log/messages file is full of messages like this
Mar 6 08:40:01 myhostname systemd: Started Session 2043 of user root.
Mar 6 08:40:01 myhostname systemd: Starting Session 2043 of user root.
Mar 6 08:40:01 myhostname systemd: Created slice user-1001.slice.
Mar 6 08:40:01 myhostname systemd: Starting user-1001.slice.
Mar 6 08:40:01 myhostname systemd: Started Session 2042 of user userx.
Mar 6 08:40:01 myhostname systemd: Starting Session 2042 of user userx.
Mar 6 08:40:01 myhostname systemd: Started Session 2041 of user root.
Mar 6 08:40:01 myhostname systemd: Starting Session 2041 of user root.
Mar 6 08:40:31 myhostname systemd: Removed slice user-1001.slice.
Mar 6 08:40:31 myhostname systemd: Stopping user-1001.slice.
Mar 6 08:41:01 myhostname systemd: Created slice user-1001.slice.
Mar 6 08:41:01 myhostname systemd: Starting user-1001.slice.
Mar 6 08:41:01 myhostname systemd: Started Session 2044 of user userx.
Mar 6 08:41:01 myhostname systemd: Starting Session 2044 of user userx.
Mar 6 08:41:21 myhostname systemd: Removed slice user-1001.slice.
Mar 6 08:41:21 myhostname systemd: Stopping user-1001.slice.
What do all of these mean, and why are they there? If this is normal background noise them it seems like an enourmous waste to of resources to log this...