/var/log/messages 파일 내용입니다

제가 분명 터미널화면에서 sudo -f /var/log/messages 로 보고 있고

또 한개의 터미널화면을 또 띄워서  sudo vi /var/log/messages로 보고 있던 중에 ...

시간이 5분 지난 상태로 계속 sudo -f /var/log/messages 로 보고 있기만 하고

웹브라우저만 띄워놓고(물론 웹브라우저띄울때도 sudo -f /var/log/messages 상에 아무런 메시지가 추가로 안보이던중...

갑자기 sudo -f /var/log/messages 화면상에 아래 처럼 slice가 발생하는데

이건 뭔가요? 검색해도 안나와서 ^^

Oct 20 20:50:01 localhost systemd: Created slice User Slice of root.
Oct 20 20:50:01 localhost systemd: Starting User Slice of root.
Oct 20 20:50:01 localhost systemd: Started Session 3 of user root.
Oct 20 20:50:01 localhost systemd: Starting Session 3 of user root.
Oct 20 20:50:01 localhost systemd: Removed slice User Slice of root.
Oct 20 20:50:01 localhost systemd: Stopping User Slice of root.
Oct 20 20:54:09 localhost systemd: Starting Cleanup of Temporary Directories...
Oct 20 20:54:09 localhost systemd: Started Cleanup of Temporary Directories.

또 이글을 쓰고 있는중에도 아래 메시지가 또 추가로 생기네요??

Oct 20 21:00:01 localhost systemd: Created slice User Slice of root.
Oct 20 21:00:01 localhost systemd: Starting User Slice of root.
Oct 20 21:00:01 localhost systemd: Started Session 4 of user root.
Oct 20 21:00:01 localhost systemd: Starting Session 4 of user root.
Oct 20 21:00:01 localhost systemd: Removed slice User Slice of root.
Oct 20 21:00:01 localhost systemd: Stopping User Slice of root.
Oct 20 21:01:01 localhost systemd: Created slice User Slice of root.
Oct 20 21:01:01 localhost systemd: Starting User Slice of root.
Oct 20 21:01:01 localhost systemd: Started Session 5 of user root.
Oct 20 21:01:01 localhost systemd: Starting Session 5 of user root.
Oct 20 21:01:01 localhost systemd: Removed slice User Slice of root.
Oct 20 21:01:01 localhost systemd: Stopping User Slice of root.