Since linux/unix agent and Service Manager version 12 we're encountering a strange behaviour with ServiceManager logging.
Each jobstart and filetransfer creates a special log-entry in ucybsmgr.log within Service Manager log directory.
The log you see is just some unnecessary information, it's not error message. As it not our Service Manager log, so it can't be rotate. Please follow our standard way to start your Service Manager to get rid of it.
The proper way to start the ServiceManager:
For more details please see Installation instruction of Automation Engine: