Follow next steps to delete the Report server:
-- Stop OPMN
opmnctl stopall
-- Stop EMConsole:
emctl stop iasconsole
-- Backup opmn.xml and targets.xml files.
-- Delete from opmn.xml the entry related to your reports server.
-- Validate opmn.xml file:
opmnctl validate opmn.xml
-- Delete from targets.xml the entry related to your reports server.
-- Start OPMN:
opmnctl stopall
-- Start EMConsole:
emctl start iasconsole