The OEM of Oracle cannot enter the problem properly.

After installing the database, enable OEM.

Emctl start dbconsole

If there is a problem with login, http://oracle11g:5500/em/console

Try to rebuild oem

Emctl stop dbconsole first

Emca-deconfig dbcontrol db-repos drop

Input oracle sid,SID must be correct, otherwise an error will be reported

After the fall of drop

Emca-config dbcontrol db-repos recreate

The listening port number must be correct. If you forget it, you can look it up in the tnsname.ora file. The specific path is / u01/oracle/11g/network/admin/tnsnames.ora.

Then enter the passwords of sys, sysman, and dbsnmp users. If you don't remember, you can log in to sqlplus / as sysdba and use alter user to change the password.

Waiting for the reconstruction to complete.

In emctl start dbconsole, if the hostname problem of / etc/hosts is prompted, add it to the environment variable of the oracle user

Export ORACLE_HOSTNAME=oracle11g

Restart the EM console login page with the sys user and password as sysdba.

PS: use emctl unsecure dbconsole to log in to OEM using http