Control File Multiplexing

Steps for control file multiplexing :

1.shutdown the database

2.decide the directory path

3.copy the control files from the exsisting location to the new location

4.edit the parameter file and place the path

5.startup

 

root> su - oracle

oracle> export ORACLE_SID=crms

oracle> sqlplus / as sysdba

SQL> startup

SQL> select name from V$controlfile;

SQL> show parameter spfile

SQL> create pfile from spfile;

                Creates pfile in the HOME/dbs directory

SQL> create pfile='/home/oracle/initcrms.ora' from spfile;

                Creates pfile in the given location.

SQL> shut immeditate

root> mkdir -p /u03/app/oracle/crms

root> chown -R oracle:oinstall /u03/app/oracle/crms/

root> chmod -R 775 /u03/app/oracle/crms/

root> su - oracle

oracle> cd /u02/app/oracle/crms/

oracle> ls

oracle> cp control01.ctl /u03/app/oracle/crms/control03.ctl

oracle> cd /u03/app/oracle/crms

oracle> ls

oracle> cd $ORACLE_HOME/dbs

oracle> pwd

oracle> ls

oracle> vi initcrms.ora

                Add the control file to the "control-files" list and save the file.

When we start the database it creates only 2 control files but not 3 as we metioned in the pfile because it reads the spfile when there are both pfile and the spfile.

                Change the name of the spfile.

oracle> mv spfilecrms.ora spfilecrms.ora.bkp

oracle> sqlplus / as sysdba

SQL> startup

SQL> select name from V$controlfile;

SQL> show parameter spfile

                If the VALUE column is empty it means that its running with pfile.

               

                ORA-00205 : error in identifying control file, check alert log for more info

SQL> select * from V$diag_info;

oracle> cd /u01/app/oracle/diag/rdbms/crms/crms/trace

oracle> ls alert_crms.log

oracle> tail -f alert_crms.log

                To come back to terminal press CTRL + C when using the tail command.