Technical Issue: Oracle 10.2.0 Oracle Enterprise Manager EM could not start, Service OracleDBconsole returns an error Code 2

Demographics: OS : Windows Server 2003 Professional R2 Enterprise Edition Service Pack 2
Database : Oracle 10gR2 10.2.0 

Message errors on logs

"Environment variable ORACLE_SID not defined. Please define it."

OC4J Configuration issue. d:\oracle\product\10.2.0\db_1/oc4j/j2ee/OC4J_DBConsole _login_orcl not found.

SOLUTIONS: Search the log file in... 

Symptons: OracleDBConsole could not start, service specific error code 2

OS : Windows Server 2003 Professional R2 Enterprise Edition Service Pack 2
Database : Oracle 10gR2 10.2.0

Possible reasons: Server name was changed, reintallation was completed using different path, hosts file incorrect setup



USING CMD COMMANDS TO FIND MORE DETAILED ERRORS

Use Windows Command Mode CMD, navigate to the Oracle \bin directory and issue the command
<Drive>:\>emctl status dbconsole


It is possible receiving this message "Environment variable ORACLE_SID not defined. Please define it."

DEFINING ENVIRONMENT VARIABLE

Find ORACLE_SID in the tnsnames.ora file
 
Use Windows Command Mode CMD, navigate to the Oracle \bin directory and issue the command

<Drive>:\>set oracle_sid=orcl 

where orcl is the ORACLE_SID


CHECKING THE ORACLEDBCONSOLE STATUS


<Drive>:\>emctl status dbconsole
OC4J Configuration issue. C:\oracle\product\10.1.0\Db_1/oc4j/j2ee/OC4J_DBConsole _amd.domainname.local_sh not found.

Check for errors in the configuration setup, server name

SYSTEM DRIVE:\WINDOWS\system32\drivers\etc\hosts review the entry or any entry related to server name.

127.0.0.1 localhost hostname.domain-name hostname

Hostname should match directory structure on Oracle:
<drive>:\oracle\product\10.2.0\db_1\oc4j\j2ee\OC4J_DBConsole_<SERVER_NAME>_orcl

How Review the EM Enterprise Manager Logs

Logs Location is:
<drive>:\oracle\product\10.2.0\db_1\<SERVER_NAME>\sysman\log

Open the files to find detailed errors: endmconsole.nohub,

Typical setup error: the system cannot find the specified path


<Drive>:\>emctl status dbconsole
Oracle Enterprise Manager 10g Database Control Release 10.2.0.1.0
Copyright (c) 1996, 2004 Oracle Corporation. All rights reserved.
http://amd.domainname.local:5503/em/console/aboutApplication
Oracle Enterprise Manager 10g is running.

TO STARTUP SERVICES
<Drive>:\>emctl start dbconsole


Useful resources:
http://arjudba.blogspot.com/2008/04/troubleshooting-dbconsole-error-oc4j.html

From Oracle Forums
http://forums.oracle.com/forums/thread.jspa?messageID=3775490&#3775490
http://forums.oracle.com/forums/thread.jspa?threadID=511549

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