问题：

[oracle@CRM ~]$ emctl start dbconsole
TZ set to US/Pacific
OC4J Configuration issue. /home/app/oracle/product/10.2.0/db_1/oc4j/j2ee/OC4J_DBConsole_CRM_CRM not found.

解决方法：重建em

用到三个指令

/*重新配置dbcosole
emca -repos drop
emca -repos create
emca -config dbcontrol db

[oracle@CRM ~]$ emca -repos drop

STARTED EMCA at Mar 6, 2012 2:59:55 PM
EM Configuration Assistant, Version 10.2.0.1.0 Production
Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Enter the following information:
Database SID: CRM
Listener port number: 1521
Password for SYS user:  
Password for SYSMAN user: 

Do you wish to continue? [yes(Y)/no(N)]: Y
Mar 6, 2012 3:01:32 PM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_02-59-55-PM.log.
Mar 6, 2012 3:01:33 PM oracle.sysman.emcp.EMReposConfig dropRepository
INFO: Dropping the EM repository (this may take a while) ...
Mar 6, 2012 3:01:33 PM oracle.sysman.emcp.util.PlatformInterface executeCommand
WARNING: Error executing /home/app/oracle/product/10.2.0/db_1/sysman/admin/emdrep/bin/RepManager -connect (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=CRM)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=CRM))) -repos_user SYSMAN -action drop -verbose -output_file /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_repos_drop_2012-03-06_03-01-33-PM.log 
Mar 6, 2012 3:01:33 PM oracle.sysman.emcp.EMReposConfig invoke
SEVERE: Error dropping the repository
Mar 6, 2012 3:01:33 PM oracle.sysman.emcp.EMReposConfig invoke
INFO: Refer to the log file at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_repos_drop_.log for more details.
Mar 6, 2012 3:01:33 PM oracle.sysman.emcp.EMConfig perform
SEVERE: Error dropping the repository
Refer to the log file at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_02-59-55-PM.log for more details.
Could not complete the configuration. Refer to the log file at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_02-59-55-PM.log for more details.
[oracle@CRM ~]$ emca -repos create

STARTED EMCA at Mar 6, 2012 3:01:47 PM
EM Configuration Assistant, Version 10.2.0.1.0 Production
Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Enter the following information:
Database SID: CRM
Listener port number: 1521
Password for SYS user:  
Password for SYSMAN user: 

Do you wish to continue? [yes(Y)/no(N)]: Y
Mar 6, 2012 3:01:58 PM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_03-01-47-PM.log.
Mar 6, 2012 3:01:58 PM oracle.sysman.emcp.EMReposConfig createRepository
INFO: Creating the EM repository (this may take a while) ...
Mar 6, 2012 3:01:58 PM oracle.sysman.emcp.EMReposConfig invoke
SEVERE: Error creating the repository
Mar 6, 2012 3:01:58 PM oracle.sysman.emcp.EMReposConfig invoke
INFO: Refer to the log file at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_repos_create_.log for more details.
Mar 6, 2012 3:01:58 PM oracle.sysman.emcp.EMConfig perform
SEVERE: Error creating the repository
Refer to the log file at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_03-01-47-PM.log for more details.
Could not complete the configuration. Refer to the log file at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_03-01-47-PM.log for more details.
[oracle@CRM ~]$ emca -config dbcontrol db

STARTED EMCA at Mar 6, 2012 3:02:10 PM
EM Configuration Assistant, Version 10.2.0.1.0 Production
Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Enter the following information:
Database SID: CRM
Listener port number: 1521
Password for SYS user:  
Password for DBSNMP user:  
Password for SYSMAN user:  
Email address for notifications (optional): 
Outgoing Mail (SMTP) server for notifications (optional): 
-----------------------------------------------------------------

You have specified the following settings

Database ORACLE_HOME ................ /home/app/oracle/product/10.2.0/db_1

Database hostname ................ CRM
Listener port number ................ 1521
Database SID ................ CRM
Email address for notifications ............... 
Outgoing Mail (SMTP) server for notifications ...............

-----------------------------------------------------------------
Do you wish to continue? [yes(Y)/no(N)]: Y
Mar 6, 2012 3:02:26 PM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /home/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/CRM/emca_2012-03-06_03-02-10-PM.log.
Mar 6, 2012 3:02:32 PM oracle.sysman.emcp.util.DBControlUtil startOMS
INFO: Starting Database Control (this may take a while) ...
Mar 6, 2012 3:04:10 PM oracle.sysman.emcp.EMDBPostConfig performConfiguration
INFO: Database Control started successfully
Mar 6, 2012 3:04:10 PM oracle.sysman.emcp.EMDBPostConfig performConfiguration
INFO: >>>>>>>>>>> The Database Control URL is http://CRM:5500/em <<<<<<<<<<<
Enterprise Manager configuration completed successfully
FINISHED EMCA at Mar 6, 2012 3:04:10 PM