Restoring the Control File - RMAN Recipes for Oracle Database 12c - page 301

Solution
If you multiplex your control files, you can take a good control file and copy it right over the top of a bad or missing
control file. You don't need to issue an RMAN restore controlfile command in this scenario. You have two
methods to get your database restarted:

• You can modify your initialization file (spfile or init.ora) so that it references only the good

remaining control file(s).

• You can copy a good control file to the location of the bad or missing control file.

Modifying the Initialization File
In the first example, control02.ctl is missing and the database won't start, so we've decided to modify the control_
files parameter in the initialization file. This example uses an spfile :

SQL> startup nomount;
SQL> alter system
set control_files='/u01/dbfile/o12c/control01.ctl' scope=spfile;
System altered.
SQL> shutdown immediate;
SQL> startup;

Copying a Good Control File
In this example, we're copying the good control file (control01.ctl) to the location of the bad control file (control02.ctl).
To do this, first shut down your database from either RMAN or SQL*Plus using this:

RMAN> shutdown immediate;

or this:

SQL> shutdown immediate;

Even though control02.ctl is bad, we suggest that you first make a copy of it. This may be useful for
troubleshooting after the fact. Here we make a copy of the bad control file:

$ cp /u01/dbfile/o12c/control02.ctl /u01/dbfile/o12c/control02.ctl.bad

Then from the Linux/Unix operating system prompt, copy the good control file to the location of the bad or
missing control file:

$ cp /u01/dbfile/o12c/control01.ctl /u01/dbfile/o12c/control02.ctl

Now from RMAN or SQL*Plus you should be able to start your database normally using the startup command as
follows:

RMAN> startup;

or

SQL> startup;