DBConsole Not starting: An instance of Oracle Enterprise Manager Database Control is already running

Attempting to start the DBConsole fails with:

An instance of Oracle Enterprise Manager Database Control is already running.

Issuing emctl stop dbconsole returns a status saying that it is successfully stopped.

emoms.trc log shows the following:

20120126 07:56:56 Thread12968 WARN http: snmehl_connect: connect failed to (<MY HOST DOMAIN:PORT>): Connection refused (error = 146)
20120126 07:56:56 Thread12968 ERROR pingManager: nmepm_pingReposURL: Cannot connect to <MY HOST DOMAIN:PORT> /em/upload/: retStatus=32
20120126 07:57:13 Thread12971 ERROR upload: Error in uploadXMLFiles. Trying again in 300.00 seconds.

CAUSE

Process did not shutdown cleanly form a previous run.

SOLUTION

1) Ensure all dbconsole related processes are not running:

ps ef | grep dbconsole
ps ef| grep emagent
kill 9 <returned pid's above>

2) rename/remove the existing pid file:

$ORACLE_HOME/<hostname>_<SID>/sysman/emctl.pid


3) start back the DB Console.