We have just installed a 10.4 OPMS and observed that the system is showing very high network bandwidth usage when the OPMS service is started. The behaviour remained the same (several hours) until the OPMS service was stopped.
The exact cause not confirmed as no network data available (source /destination addresses) Problem was believed to be due to insufficient space in /var/lib to successfully download docker images resulting in repeated retries.
Release : 10.4
Component : App Synthetic Monitor OPMS
Once the file system size for /var was increased network traffic dropped. In OPMS 10.5 downloads are logged so this situation will be easier to confirm.
Since version 10.4 the OPMS installation process does not download all the docker images it requires during the installation. These are downloaded on the first startup of the OPMS. So the installation is not complete until the OPMS has started and all services are running correctly. In OPMS 10.5 the system will log all downloads so determining if there is a problem in this area will be easier to determine.
If a separate /var system has been configured on the system (this is contrary to the installation instructions in the documentation which if followed result a single / partition) then a minimum of 10Gb should be allocated and the free space monitored.