---------------------验证互为镜像功能---------------------
窗口1
cd /oracle/app/oradata/ecom
rm control03.ctl
窗口2
SQL> startup force;
ORACLE instance started.
Total System Global Area 285212672 bytes
Fixed Size 1218992 bytes
Variable Size 92276304 bytes
Database Buffers 188743680 bytes
Redo Buffers 2973696 bytes
ORA-00205: error in identifying control file, check alert log for more info
【加载到Nomount状态时，读取参数文件，在参数文件中，指向控制文件，有3个控制文件。】
窗口1
cp control01.ctl control03.ctl
窗口2
alter database mount;
alter database open;
控制文件复制回来，正常了，验证了镜像功能
---------------------------多路复用------------------------------------
窗口1
SQL> alter system set control_files ='/oracle/app/oradata/ecom/control01.ctl','/home/oracle/ctrl02.ctl' scope=spfile;
窗口2
cp /oracle/app/oradata/ecom/control01.ctl /home/oracle/ctrl02.ctl
窗口1
SQL> shutdown immediate;
窗口2
rm control02.ctl control03.ctl
窗口1
SQL> startup
SQL> show parameter control_files;