Greetings.
I'm getting similar messages after updating to 4.1.9 Arrakis.
The difference is my web interface experience some difficulties with the graphics in the main menu options (if I go directly to a submenu all working fine).
"Does not exist Service rrdcached
Date: Wed, 22 Aug 2018 18:11:47
Action: restart
Host: omv
Description: process is not running"
I also getting this one
"Exists Service rrdcached
Date: Wed, 22 Aug 2018 18:12:19
Action: alert
Host: omv
Description: process is running with pid 1038"