Here I have a 11g Grid control running on Linux x86_64.
To add a database in the Grid control, Open OEM grid control page –> targets –> databases
Click on ADD button, then the below screenshot will appear
Select the hostname from the list shown and click continue.
NOTE : The hostnames are displayed when that server is configured with the GRID server, if not configure.
It will take some time to find and display the targets and the listeners found on that host(server).
Select the target you want to add and the listener associated with it. Then click on configure button for the selected target and you’ll get below screen.
Give ‘dbsnmp’ password and fill all the fields correctly then click next and ok.
Done, now you’ll see your target(database) in the OEM grid database list.