oracle emctl is not working

if oracle emctl is not working or not starting .Need to check down one by one :-

1. is emctl  start responds ?

2. if yes , then check 1158 port is open or not ?

3. if port is not opening then request to IT team to open it , if its opened then move to next step .

4.check the firewall at your end , some times firewall prevents to start the OracleDbConsoleorcl services .

5.check the dbsnmp account status ,it may be locked or its password has been expired, unlock it and if require change the password.

6. If everything is OK , then reconfigure the OEM.

Here i am sharing the steps to configre the EM from scratch , even if the database is running , please get approval to before run on Production :-

1. Please set the following environment variables

ORACLE_SID

ORACLE_HOSTNAME

2.Delete DB Control Configuration Files Manually:

- Remove the following directories from your filesystem:

<ORACLE_HOME>/<hostname_sid>

<ORACLE_HOME>/oc4j/j2ee/OC4J_DBConsole_<hostname>_<sid>

3. Delete DB Control Repository Objects Manually

Logon SQLPLUS as user SYS or SYSTEM, and drop the sysman account and management

objects:

SQL> SHUTDOWN IMMEDIATE;

SQL> STARTUP RESTRICT;

SQL> EXEC sysman.emd_maintenance.remove_em_dbms_jobs;

SQL> EXEC sysman.setEMUserContext('',5);

SQL> REVOKE dba FROM sysman;

SQL> DECLARE

CURSOR c1 IS

SELECT owner, synonym_name name

FROM dba_synonyms

WHERE table_owner = 'SYSMAN';

BEGIN

FOR r1 IN c1 LOOP

IF r1.owner = 'PUBLIC' THEN

EXECUTE IMMEDIATE 'DROP PUBLIC SYNONYM '||r1.name;

ELSE

EXECUTE IMMEDIATE 'DROP SYNONYM '||r1.owner||'.'||r1.name;

END IF;

END LOOP;

END;

/

SQL> DROP USER mgmt_view CASCADE;

SQL> DROP ROLE mgmt_user;

SQL> DROP USER sysman CASCADE;

SQL> ALTER SYSTEM DISABLE RESTRICTED SESSION;

The above will completely delete the DB Control repository from the database;

under certain circumstances (e.g. you want to recreate the repository later on)

the following statements may be sufficient to remove the repository:

Logon SQLPLUS as user SYS or SYSTEM, and drop the sysman account and

management objects:

SQL> drop user sysman cascade;

SQL> drop role MGMT_USER;

SQL> drop user MGMT_VIEW cascade;

SQL> drop public synonym MGMT_TARGET_BLACKOUTS;

SQL> drop public synonym SETEMVIEWUSERCONTEXT;

4. Create the DB Control Repository Objects and Configuration Files

<ORACLE_HOME>bin/emca -config dbcontrol db -repos drop

<ORACLE_HOME>bin/emca -config dbcontrol db -repos create

5. Then check the following:

5.1 emctl start dbconsole (any errors?)

5.2 emctl status dnconsole

5.3 emctl status agent

5.4 emctl upload