Multiplexing of Oracle control files

Concept ：
The control file is Oracle Database is a very important file , The structure information of the current database is recorded , At the same time, it also contains the information of data files and log files, as well as the related status , Archive information and so on , A database has at least one control file , It is strongly recommended that more than one control document , The backup of each control file should be placed on a different disk .

Configuration steps ：
1. Create a directory for storing multiplexing control files
mkdir -p /flash_recover_area/controfile
2. View existing control files
show parameter contro;

NAME				     TYPE
------------------------------------ --------------------------------
VALUE
------------------------------
control_file_record_keep_time	     integer
7
control_files			     string
/u01/app/oracle/oradata/jfdb/c
ontrol01.ctl, /u01/app/oracle/
oradata/jfdb/control02.ctl
control_management_pack_access	     string

NAME				     TYPE
------------------------------------ --------------------------------
VALUE
------------------------------
DIAGNOSTIC+TUNING

3. add to control03.ctl

alter system set control_files='/u01/app/oracle/oradata/jfdb/control01.ctl','/u01/app/oracle/oradata/jfdb/control02.ctl','/flash_recover_area/controfile/control03.ctl' scope=spfile;

4. Close the database

shutdown immediater;

5. Copy control01.ctl To /flash_recover_area/controfile/ Directory and rename control03.ctl

cp  /u01/app/oracle/oradata/jfdb/control01.ctl  /flash_recover_area/controfile/control03.ctl

6. Start database , Check the number of control files
startup
show parameter contro;

SQL> show parameter contro;

NAME				     TYPE
------------------------------------ --------------------------------
VALUE
------------------------------
control_file_record_keep_time	     integer
7
control_files			     string
/u01/app/oracle/oradata/jfdb/c
ontrol01.ctl, /u01/app/oracle/
oradata/jfdb/control02.ctl, /f
lash_recover_area/controfile/c
ontrol03.ctl
control_management_pack_access	     string

NAME				     TYPE
------------------------------------ --------------------------------
VALUE
------------------------------
DIAGNOSTIC+TUNING