If you understand what the process does it helps understand which log you would look at.
Main communication process which controls connectivity, firewall communication, patch information, and space checks. This process writes to the CVD.log and cvfwd.log.
Forwards events generated on the local machine to the CommServe. In addition it helps the CommServe to browse the application data on local machine. This process writes to the EvMgrC.log
Responsible for communicating with CommCell Console and receive the events from the Clients and/or MediaAgents. This process writes to the EvMgrS.log
Responsible for running and controlling jobs and also communicate with the available resources. This process writes to the JobManager.log