This document tells us how to multiplex control file in ORACLE databases.Controlfile contains crucial information about the database. It contains information about
1) Database creation time.
2) Time stamp of database.
3) Data files and redo log file information.
4)check point information.
5)log sequence number.
6) backup information.
7)Time stamp of database.
By based on this information control file is crucial for database. But the size of control file is always small. Multiplexing control is an important task in database admistration.It is always better to maintain multiple copies of control file in different disk location's. If one control file will have corrupted we will demultiplex the control file and up the database otherwise we will copy the control file(which is not corrupted) to the corrupted location. I am giving steps for control file multiplexing below.
step 1: export ORACLE_SID=<Instance Name>
step 2: connect to sql prompt with sysdba privilege.
step 3:Then check control file location of database.
command: sql>show parameter control_files
step 4:show parameter spfile.
step 5:If database is running by using spfile then go to step 6
step 6:update the information of new control file location in spfile.
command:sql>altersystem set control_files='/disk1/oradata/db1/control.ctl','/disk2/oradata/db1/control.ctl' scope=spfile;
step 7:down the database.
command:sql>shutdown immediate.
step 8:copy the control file to the new location by using operating system commands.
$cp <old location> <new location>
step 9:startup the database
command:sql>startup
step 10: If database had started with pfile,then manually update the value of the parameter in init.ora .execute the steps form step 7
1) Database creation time.
2) Time stamp of database.
3) Data files and redo log file information.
4)check point information.
5)log sequence number.
6) backup information.
7)Time stamp of database.
By based on this information control file is crucial for database. But the size of control file is always small. Multiplexing control is an important task in database admistration.It is always better to maintain multiple copies of control file in different disk location's. If one control file will have corrupted we will demultiplex the control file and up the database otherwise we will copy the control file(which is not corrupted) to the corrupted location. I am giving steps for control file multiplexing below.
step 1: export ORACLE_SID=<Instance Name>
step 2: connect to sql prompt with sysdba privilege.
step 3:Then check control file location of database.
command: sql>show parameter control_files
step 4:show parameter spfile.
step 5:If database is running by using spfile then go to step 6
step 6:update the information of new control file location in spfile.
command:sql>altersystem set control_files='/disk1/oradata/db1/control.ctl','/disk2/oradata/db1/control.ctl' scope=spfile;
step 7:down the database.
command:sql>shutdown immediate.
step 8:copy the control file to the new location by using operating system commands.
$cp <old location> <new location>
step 9:startup the database
command:sql>startup
step 10: If database had started with pfile,then manually update the value of the parameter in init.ora .execute the steps form step 7
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