How can I start Oracle Enterprise manager after restarting the Red Hat Server?

Solution 1:

Try to re-configure em completely

emctl stop dbconsole
emca -repos drop
emca -repos create
emca -deconfig dbcontrol db
emca -config dbcontrol db

The best regards

Solution 2:

try

emctl start dbconsole

if it does not helps - try to re-configure em

emca -config dbcontrol db