版本： em12c 12.1.0.4 OS : redhat 5.7 x86_bit （CentOS6.2,测试过，当时因glibc*.i686包安装一直报错，所以放弃了） == em12c 安装，就不说了，网上一大把，或者查看官方文档： ==这里涉及一些参数配置： Check the CBO stats gathering jobDisable the

Check the CBO stats gathering job	Disable the stats gathering job

 1.Check the processes instance parameter value
 The processes instance parameter needs to be set to at least 300.

 2.Check the session_cached_cursors instance parameter value.
 The session_cached_cursors instance parameter should be set to 300.
 Any value between 200 and 500, inclusive, will be accepted.

 3.Check the job_queue_processes instance parameter value.
 The job_queue_processes instance parameter should be set to 20.

 4.Check the shared_pool_size instance parameter value.
 The shared_pool_size instance parameter should be set to
 at least 600 megabytes or roughly one third of the sga_target size.

 5. Check the redo log size.
 The size of the EM database instance should be 300 megabytes or greater.
 Generally, there should be 3 or more redo logs available of this size.

 6. Ensure that the EM tablespace has at least one datafile set to autoextensible
 Add at least one datafile with the autoextend attribute to the EM tablespace

 7.Check the open_cursors instance parameter value.
 The open_cursors instance parameter should be set between 300 and 400, inclusive.

 8.Check the sga_target instance parameter value.
 The sga_target instance parameter should be set to at least 2 gigabytes, and
 roughly twice the size of the pga_aggregate_target setting.

 9.Check for invalid objects in the EM repository
 Compile all invalid objects in the EM repository

==> 如果之前你的db 安装了EM 的话，那么这条命令可以帮助你：

[oracle@em12c ~]$ emca -deconfig dbcontrol db -repos drop -SYS_PWD password -SYSMAN_PWD password STARTED EMCA at Jul 24, 2014 10:13:13 AM EM Configuration Assistant, Version 11.2.0.3.0 Production Copyright (c) 2003, 2011, Oracle. All rights reserved. Enter the following information: Database SID: em12c Listener port number: 1521 ---------------------------------------------------------------------- WARNING : While repository is dropped the database will be put in quiesce mode. ---------------------------------------------------------------------- Do you wish to continue? [yes(Y)/no(N)]: Y Jul 24, 2014 10:13:22 AM oracle.sysman.emcp.EMConfig perform INFO: This operation is being logged at /dba/app/oracle/cfgtoollogs/emca/em12c/emca_2014_07_24_10_13_12.log. Jul 24, 2014 10:13:23 AM oracle.sysman.emcp.util.DBControlUtil stopOMS INFO: Stopping Database Control (this may take a while) ... Jul 24, 2014 10:13:46 AM oracle.sysman.emcp.EMReposConfig invoke INFO: Dropping the EM repository (this may take a while) ... Jul 24, 2014 10:15:57 AM oracle.sysman.emcp.EMReposConfig invoke INFO: Repository successfully dropped Enterprise Manager configuration completed successfully FINISHED EMCA at Jul 24, 2014 10:16:00 AM

被监控服务器，上关于sudo命令的设置： ---/usr/local/etc/sudoers #
## Allow root to run any commands anywhere root ALL=(ALL) ALL oracle ALL=(ALL) ALL -->添加一行
#Defaults requiretty -->注释掉 Defaults:oracle !requiretty -->添加oracle # # Refuse to run if unable to disable echo on the tty. This setting should also be # changed in order to be able to use sudo without a tty. See requiretty above. # #Defaults !visiblepw -->注释掉 Defaults visiblepw -->添加

==>被监控服务器，agent 卸载，其实EM12C 主服务器，卸载方式同样，涉及sysman,sysaux 下的一些表空间记得清楚）（一）卸载插件 eg： [oracle@dominic4 plugins]$ pwd
/em12c/plugins
[oracle@dominic4 plugins]$ ls
oracle.em.savf.discovery.plugin_12.1.0.2.0 oracle.sysman.emas.discovery.plugin_12.1.0.6.0
oracle.em.soav.discovery.plugin_12.1.0.4.0 oracle.sysman.oh.agent.plugin_12.1.0.4.0
oracle.sysman.db.agent.plugin_12.1.0.6.0 oracle.sysman.oh.discovery.plugin_12.1.0.4.0
oracle.sysman.db.discovery.plugin_12.1.0.6.0 oracle.sysman.xa.discovery.plugin_12.1.0.6.0

[oracle@dominic4 ~]$ /em12c/core/12.1.0.4.0/oui/bin/runInstaller -deinstall -silent "REMOVE_HOMES={/em12c/plugins/oracle.sysman.xa.discovery.plugin_12.1.0.6.0,/em12c/plugins/oracle.sysman.db.discovery.plugin_12.1.0.6.0,/em12c/plugins/oracle.sysman.db.agent.plugin_12.1.0.6.0}" -removeALLFiles -invPtrLoc /etc/oraInst.loc

----plugins 下的所有 oracle.* 都需要删除。

（二） 卸载sbin
[oracle@dominic4 ~]$ /em12c/core/12.1.0.4.0/oui/bin/runInstaller -deinstall -silent "REMOVE_HOMES={/em12c/sbin}" -removeALLFiles -invPtrLoc /etc/oraInst.loc
Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB. Actual 3498 MB Passed
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2014-08-11_11-59-57AM. Please wait ...[oracle@dominic4 ~]$ Oracle Universal Installer, Version 11.1.0.12.0 Production
Copyright (C) 1999, 2014, Oracle. All rights reserved.

Starting deinstall

Deinstall in progress (Monday, August 11, 2014 12:00:01 PM CST)
............................................................... 100% Done.

Deinstall successful

End of install phases.(Monday, August 11, 2014 12:00:02 PM CST)
End of deinstallations
Please check '/dba/app/oraInventory/logs/silentInstall2014-08-11_11-59-57AM.log' for more details.
( 三）卸载 agent home [oracle@dominic4 ~]$ /em12c/core/12.1.0.4.0/oui/bin/runInstaller -deinstall -silent "REMOVE_HOMES={/em12c/core/12.1.0.4.0}" -removeALLFiles -invPtrLoc /etc/oraInst.loc
Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB. Actual 3498 MB Passed
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2014-08-11_12-03-20PM. Please wait ...[oracle@dominic4 ~]$ Oracle Universal Installer, Version 11.1.0.12.0 Production
Copyright (C) 1999, 2014, Oracle. All rights reserved.

Starting deinstall

Deinstall in progress (Monday, August 11, 2014 12:03:23 PM CST)
Configuration assistant "Agent Deinstall Assistant" succeeded
............................................................... 100% Done.

Deinstall successful
End of install phases.(Monday, August 11, 2014 12:04:18 PM CST) End of deinstallations Please check '/dba/app/oraInventory/logs/silentInstall2014-08-11_12-03-20PM.log' for more details. （四） 删除目录
rm -rf /em12c/*
history -c