2 - 3 minutes readWhat will you do, if RMAN metadata corrupt?

Above error may occur if:

a) ASM disk(s) is not visible on the operating system.
b) asm_diskstring parameter is not set correctly on ASM instance(s)
c) ASM metadata in disk is overwritten or corrupted

If above C point is the case, we may need to re-create our ASM instance(s) and disk group(s).

The steps are:

1. Ensure that you have a prior RMAN backup of all databases using ASM
2. Shut down your ASM instance(s)
3. Re-create your ASM disk group(s)
4. Restore databases

Now we will create a case about above mention error:

Database & ASM Details:

Host Name: SUN1
IP: 192.168.126.2
Oracle Home: /export/home/oracle/oracle/product/db_1
DB Name: INDIAN
PORT: 1521
ASM DISK GROUP: DB_DATA01

Step 1 Backup your Database, Archive logs and Control files

$rman target /
RMAN> backup device type disk format ‘/export/home/oracle/rman/DB_%U’ database plus archivelog;
RMAN> backup device type disk format ‘/export/home/oracle/rman/ctrlf_%U’ current controlfile;

Step 2 Manually make copies of your spfiles.

SQL> create pfile=’/export/home/oracle/rman/initINDIAN.ora’ from spfile;

Step 3 Shutdown Database and ASM Instance.

Create Case:

Destroying existing data on a file system partition:/dev/rdsk/c0d1s0 by using dd command:
Log in As a Root user and execute:

#dd if=/dev/zero of=/dev/

Now try to start ASM Instance. Error Accord

ORA-15032: not all alterations performed
ORA-15063: diskgroup “” lacks quorum of 2 PST disks; 0 found

Step 4 Re-create your ASM disk group(s)

Step 5 Restore database

$ export ORACLE_SID=INDIAN
$ sqlplus /nolog
SQL> conn / as sysdba
Connected to an idle instance.
SQL> startup nomount pfile=’/export/home/oracle/rman/initINDIAN.ora’;

$ rman target /
RMAN> restore controlfile from ‘/export/home/oracle/rman/ctrlf_05m7m22o_1_1’;
RMAN> alter database mount;
RMAN> restore database;
RMAN> recover database;
RMAN> alter database open resetlogs;

Step 6 Connect to the ASM instance and get the control file name.

sqlplus ‘/ as sysdba’
SQL> select name, alias_directory from v$asm_alias;

Look for the controlfile name under the CONTROLFILE directory eg: Current.256.746263173

Step 7 Edit the init.ora and change the control_files parameter to point to the one identified from the ASM v$asm_alias view.