Discgroup is not compatible for database usage while using 11g dbca with Custom Database template.

Scenario:

DB creation using DBCA in exadata machine. An 8 node RAC DB is being created.

DB Version: 11.2.0.3.0

Error:

Discgroup "+DATA_SLCC24" is not compatible for
database usage. Database compatible attribute of
diskgroup should be the same or lower than the database
compatible initialization parameter value.
Database compatible parameter is set to "11.2.0.0.0"
and the diskgroup database compatibility attribute is set
 to "11.2.0.2". 

Reason: 


The error denotes that the compatible parameter set in the database initialization parameter is lower than the compatible.rdbms set for the diskgroup in ASM. In this case the database compatible parameter was set to 11.2.0.0.0 and the diskgroup compatible.rdbms is set to 11.2.0.2.0.

We can verify the ASM compatible settings by issuing following query after connecting to the ASM instance.

select group_number, name, compatibility, database_compatibility from v$asm_diskgroup;

ASM instances with a compatible value set to equal or greater than compatible.asm can mount the diskgroup. So in this case we have to change the setting in DB level.

DBCA uses in built templates to create the DB. The templates are by default stored in $ORACLE_HOME/assistants/dbca/templates folder.

We need to find out and edit the attribute in the right template and reinvoke dbca.

Solution:

Move to $ORACLE_HOME/assistants/dbca/templates location. Find the template that is used by you. I have used "Custom Database" template. The template file for "Custom Database" option is New_Database.dbt. So take  a backup of that template for safety and open the "New_Database.dbt" file using "vi" editor.

Search for the string compatible. Change its value to be equal to (or greater than) the corresponding ASM value. For example as shown below


   <initParam name="compatible" value="11.2.0.0.0"/>    => This was my original setting

I changed it to 11.2.0.2.0 and saved the file and quit


Exit from the dbca session if you have not already, and restart dbca. It should go through now.