EM 12c系统由下列组件构成：
1.Oracle Management Agent（管理代理）
2.Oracle Management Service（管理服务）
3.Oracle Management Repository（管理资料档案库）
4.Plug-Ins（插件）
5.Enterprise Manager Cloud Control Console（EMCC控制台）
EM12c组件之间的 关系如下图
server 端的准备：
Oracle RDBMS 11.2.0.4
操作系统RedHat7 防火墙关闭
如果之前安装了EM，需要删除
$ORACLE_HOME/bin/emca -deconfig dbcontrol db -repos drop
OMS安装
1检查CPU
cat /proc/cpuinfo |grep process
2检查内存
free
3检查硬盘空间
df -h
系统内核参数调整
在/etc/sysctl.conf中添如下内核参数：
kernel.shmmax = 4294967296
修改 /etc/redhat-release
Red Hat Enterprise Linux Server release 6.0 (Maipo)
yum -y install glibc-devel-2.17-55.el7.i686.rpm
安装路径信息
mkdir -p /home/oracle/app/oracle/mw #Middleware Home
mkdir -p /home/oracle/app/oracle/agent #Agent Base
mkdir -p /home/oracle/app/oracle/mw/gc_inst #OMS Instance Base
mkdir -p /home/oracle/app/oracle/mw/oms #OMS Home
修改数据库参数：
exec DBMS_AUTO_TASK_ADMIN.DISABLE(client_name => 'auto optimizer statscollection',operation => NULL,window_name => NULL);
alter system set processes= 500 scope=spfile;
alter system set session_cached_cursors=500 scope=spfile;
alter system set shared_pool_size=650M scope=spfile;
alter system set job_queue_processes=22 scope=spfile;
alter database add logfile size 320M;
alter system set open_cursors=350 scope=spfile;
alter system set sga_target=2g scope=spfile;
ALTER SYSTEM SET pga_aggregate_target=1G SCOPE=SPFILE;
alter system set parallel_max_servers = 1 scope=both;
server 端安装：
将下载好的三个ZIP文件解压到同一目录
[oracle@ydorcl ~]$ cd /home/app/em12c/
[oracle@ydorcl em12c]$ ls
bipruntime jdk oms release_notes.pdf runInstaller wls
install libskgxn plugins response stage WT.zip
[oracle@ydorcl em12c]$ ./runInstaller
遇到的报错：
1
解决方法：
ulimit -n 4096
2
禁用11G的自动收集job
SQL> select client_name,status from DBA_AUTOTASK_CLIENT; CLIENT_NAME STATUS ---------------------------------------------------------------- --------
auto optimizer stats collection ENABLED auto space advisor ENABLED sql tuning advisor ENABLED
begin DBMS_AUTO_TASK_ADMIN.DISABLE(client_name => 'auto optimizer stats collection', operation => NULL, window_name => NULL); end;
/ PL/SQL procedure successfully completed.
SQL> select client_name,status from DBA_AUTOTASK_CLIENT; CLIENT_NAME STATUS ---------------------------------------------------------------- --------
auto optimizer stats collection DISABLED auto space advisor ENABLED sql tuning advisor ENABLED
3
/home/oracle/app/oracle/mw/Oracle_WT/lib/sysliblist 添加：
-ldms2