在grid control没有出来之前，ORACLE数据库的监控和管理可以通过dbconsole来完成。
有了dbconsole，对数据库性能和是否需要升级硬件等等的把控就显得轻松很多，否则的话还需要借助其他的监控工具，如cacti,nagios,hq等等。
在创建数据库的时候如果没有选择安装EM，那么后期如果需要配置dbconsole的话，可以通过emca命令来完成。
下面来看看一个简单的配置过程:
1. 首先要修改一下数据库参数,以满足dbconsole的需求。
alter system set
shared_pool_size
=80M scope=both;
alter system set job_queue_processes=1 scope=both;
2. 找几个没有被占用的端口
3. 创建资料库，配置agent和dbconsole,启动
emca -config dbcontrol db -repos create -silent -HOST digoal.sky-mobi.com.hz -SID digoal -PORT 1521 -ORACLE_HOME /opt/oracle/product/10.2.0/db_1 -DBSNMP_PWD oracle -SYSMAN_PWD oracle -SYS_PWD oracle -DBCONTROL_HTTP_PORT 8003 -AGENT_PORT 8004 -RMI_PORT 8005 -JMS_PORT 8006
说到创建资料库，配置agent和dbconsole，马上又看到了两年前设计的监控系统的影子。
http://blog.163.com/digoal@126/blog/static/16387704020105444545420/ 所以IT很多东西其实是相通的。
具体的语法可以参考:
【参考】
emca --help
/opt/oracle/product/10.2.0/db_1/bin/emca [operation] [mode] [dbType] [flags] [parameters]
-h | --h | -help | --help: prints this help message
-version: prints the version
-config dbcontrol db [-repos (create | recreate)] [-cluster] [-silent] [-backup] [parameters]: configure Database Control for a database
-config centralAgent (db | asm) [-cluster] [-silent] [parameters]: configure central agent management
-config all db [-repos (create | recreate)] [-cluster] [-silent] [-backup] [parameters]: configure both Database Control and central agent management
-deconfig dbcontrol db [-repos drop] [-cluster] [-silent] [parameters]: de-configure Database Control
-deconfig centralAgent (db | asm) [-cluster] [ -silent] [parameters]: de-configure central agent management
-deconfig all db [-repos drop] [-cluster] [-silent] [parameters]: de-configure both Database Control and central agent management
-addInst (db | asm) [-silent] [parameters]: configure EM for a new RAC instance
-deleteInst (db | asm) [-silent] [parameters]: de-configure EM for a specified RAC instance
-reconfig ports [-cluster] [parameters]: explicitly reassign Database Control ports
-reconfig dbcontrol -cluster [-silent] [parameters]: reconfigures RAC Database Control deployment
-displayConfig dbcontrol -cluster [-silent] [parameters]: displays information about the RAC Database Control configuration
-upgrade (db | asm | db_asm) [-cluster] [-silent] [parameters]: upgrades an earlier version of the EM configuration to the current version
-restore (db | asm | db_asm) [-cluster] [-silent] [parameters]: restores the current version of the EM configuration to an earlier version
Parameters and Options:
[parameters]: [ -respFile fileName ] [ -paramName paramValue ]*
db: perform configuration operation for a database (including databases that use ASM)
asm: perform configuration operation for an ASM-only instance
db_asm: perform upgrade/restore operation for a database and an ASM instance
-repos create: create a new Database Control repository
-repos drop: drop the current Database Control repository
-repos recreate: drop the current Database Control repository and recreate a new one
-cluster: perform configuration operation for a RAC database
-silent: perform configuration operation without prompting for parameters
-backup: configure automatic backup for a database
Parameters for single instance databases
HOST: Database hostname
SID: Database SID
PORT: Listener port number
ORACLE_HOME: Database ORACLE_HOME
HOST_USER: Host username for automatic backup
HOST_USER_PWD: Host user password for automatic backup
BACKUP_SCHEDULE: Automatic backup schedule (HH:MM)
EMAIL_ADDRESS: Email address for notifications
MAIL_SERVER_NAME: Outgoing Mail (SMTP) server for notifications
ASM_OH: ASM ORACLE_HOME
ASM_SID: ASM SID
ASM_PORT: ASM port
ASM_USER_ROLE: ASM user role
ASM_USER_NAME: ASM username
ASM_USER_PWD: ASM user password
SRC_OH: ORACLE_HOME for the database to be upgraded
DBSNMP_PWD: Password for DBSNMP user
SYSMAN_PWD: Password for SYSMAN user
SYS_PWD: Password for SYS user
DBCONTROL_HTTP_PORT: Database Control HTTP port
AGENT_PORT: EM agent port
RMI_PORT: RMI port for Database Control
JMS_PORT: JMS port for Database Control
Additional Parameters for cluster databases
CLUSTER_NAME: Cluster name
DB_UNIQUE_NAME: Database unique name
SERVICE_NAME: Service name
EM_NODE: Database Control node name
EM_SID_LIST: Agent SID list [comma separated]
