I am new to configuring Orion so please bear with me...
We have a few Linux based boxes and the results from trying to monitor these with 8.5 has been problematic at best. In the two instances so far, we have had a system use 9,588% of its RAM (very VERY efficient box, don'tcha know) and another one that is all but dead registering 100% of CPU usage constantly.
I saw some posts about similiar issues but I am unsure if they apply to the current revision of Orion. We are using 8.5... will it help to go to 8.5.1? Is there something else that would help?