转自：http://tonykorn97.itpub.net/post/6414/408368

Oracle10G的EM采用了web方式，并且分成了2个产品，database control和grid control。这里主要介绍如何创建单数据的dbcontrol。Grid control需要下载单独的光盘安装。
在用DBCA建库的时候，可以选择是否启用dbcontrol，启用的话需要在数据库中建立一个sysman的schema，用于保存EM的一些数据，这个就是EM的资料库(repository)。
使用命令行工具emca可以创建，修改，重建或者删除dbcontrol的配置。

SQL> select * from v$version;
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
SQL>
由于要在数据库中建EM资料库，数据库和监听都必须已经启动并正常工作。
配置dbcontrol
[oracle@oracle10 ~]$ emca -config dbcontrol db
STARTED EMCA at Oct 27, 2007 9:33:48 AM
EM Configuration Assistant, Version 10.2.0.1.0 Production
Copyright (c) 2003, 2005, Oracle. All rights reserved.
Enter the following information:
Database SID: orcl
Database Control is already configured for the database orcl
You have chosen to configure Database Control for managing the database orcl
This will remove the existing configuration and the default settings and perform a fresh configuration
Do you wish to continue? [yes(Y)/no(N)]: Y
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 ................ /opt/oracle/product/10.2.0/Database
Database hostname ................ oracle10
Listener port number ................ 1521
Database SID ................ orcl
Email address for notifications ............... 
Outgoing Mail (SMTP) server for notifications ...............
-----------------------------------------------------------------
Do you wish to continue? [yes(Y)/no(N)]: Y
Oct 27, 2007 9:35:12 AM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /opt/oracle/product/10.2.0/Database/cfgtoollogs/emca/orcl/emca_2007-10-27_09-33-46-AM.log.
Oct 27, 2007 9:35:33 AM oracle.sysman.emcp.util.DBControlUtil stopOMS
INFO: Stopping Database Control (this may take a while) ...
Oct 27, 2007 9:36:39 AM oracle.sysman.emcp.ParamsManager getLocalListener
WARNING: Error retrieving listener for oracle10
Oct 27, 2007 9:36:54 AM oracle.sysman.emcp.util.DBControlUtil startOMS
INFO: Starting Database Control (this may take a while) ...
Oct 27, 2007 9:39:51 AM oracle.sysman.emcp.EMDBPostConfig performConfiguration
INFO: Database Control started successfully
Oct 27, 2007 9:39:53 AM oracle.sysman.emcp.EMDBPostConfig performConfiguration
INFO: >>>>>>>>>>> The Database Control URL is http://oracle10:5500/em <<<<<<<<<<<
Enterprise Manager configuration completed successfully
FINISHED EMCA at Oct 27, 2007 9:39:53 AM
[oracle@oracle10 ~]$
删除数据库的 Database Control配置
[oracle@oracle10 ~]$ emca -deconfig dbcontrol db
STARTED EMCA at Oct 27, 2007 10:44:24 AM
EM Configuration Assistant, Version 10.2.0.1.0 Production
Copyright (c) 2003, 2005, Oracle. All rights reserved.
Enter the following information:
Database SID: orcl
Do you wish to continue? [yes(Y)/no(N)]: Y
Oct 27, 2007 10:44:47 AM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /opt/oracle/product/10.2.0/Database/cfgtoollogs/emca/orcl/emca_2007-10-27_10-44-22-AM.log.
Oct 27, 2007 10:44:52 AM oracle.sysman.emcp.util.DBControlUtil stopOMS
INFO: Stopping Database Control (this may take a while) ...
Oct 27, 2007 10:48:13 AM oracle.sysman.emcp.EMReposConfig stopDBMSJobs
WARNING: Error initializing SQL connection. SQL operations cannot be performed
Oct 27, 2007 10:48:13 AM oracle.sysman.emcp.EMReposConfig invoke
WARNING: Unable to remove DBMS jobs.
Enterprise Manager configuration completed successfully
FINISHED EMCA at Oct 27, 2007 10:51:01 AM
[oracle@oracle10 ~]$
此时运行emctl命令的显示是：
[oracle@oracle10 ~]$ emctl status dbconsole
TZ set to PRC
OC4J Configuration issue. /opt/oracle/product/10.2.0/Database/oc4j/j2ee/OC4J_DBConsole_oracle10_orcl not found.

常用的命令语法：
emca -repos create创建一个EM资料库
emca -repos recreate重建一个EM资料库
emca -repos drop删除一个EM资料库
emca -config dbcontrol db配置数据库的 Database Control
emca -deconfig dbcontrol db删除数据库的 Database Control配置
emca -reconfig ports 重新配置db control和agent的端口
emctl start console启动EM console服务，使用前需要先设置ORACLE_SID环境变量
emctl stop console停止EM console服务，使用前需要先设置ORACLE_SID环境变量
注：通过查看$ORACLE_HOME/install/portlist.ini 文件可以知道当前dbcontrol正在使用的端口，默认dbcontrol http端口1158，agent端口3938。如果要重新配置端口，可以使用如下命令：
emca -reconfig ports -dbcontrol_http_port 1159
emca -reconfig ports -agent_port 3939
使用命令行工具emctl可以启动/停止console服务，察看服务状态等。