How to Downgrade 12c Grid Infrastructure Standalone to 11g R2

How to Reconfigure Oracle Restart (Doc ID 986740.1)

Solution

1. Remove Oracle Restart configuration

This step should be performed as privileged (root) user.

# $GRID_HOME/crs/install/roothas.pl -deconfig -force

The expected result is "Successfully deconfigured Oracle Restart stack".

2. Reconfigure Oracle Restart

This step should also be performed as privileged (root) user.

# $GRID_HOME/crs/install/roothas.pl

The expected result is “Successfully configured Oracle Grid Infrastructure for a Standalone Server”

3. Add ASM back to Oracle Restart configuration

This step should be performed as Grid Infrastructure owner (grid user).

$ srvctl add asm

The expected result is no output, just a return to the operating system prompt.

4. Start up ASM instance

This step should be performed as Grid Infrastructure owner (grid user).

$ srvctl start asm

That should start ASM. Note that at this time there will be no ASM initialization or server  parameter file.

5. Recreate ASM server parameter file (SPFILE)

This step should be performed as Grid Infrastructure owner (grid user).

Create a temporary initialization parameter file (e.g. /tmp/init+ASM.ora) with the following content (specify your own disk group names):

asm_diskgroups='DATA','RECO'
instance_type='asm'
large_pool_size=12M
remote_login_passwordfile='EXCLUSIVE'

Mount the disk group where the new server parameter file (SPFILE) will reside (e.g. DATA) and create SPFILE:

$ sqlplus / as sysasm

SQL> alter diskgroup DATA mount;
Diskgroup altered.

SQL> create spfile='+DATA' from pfile='/tmp/init+ASM.ora';
File created.

SQL> show parameter spfile
NAME TYPE VALUE
------- ------- -------------------------------------------------
spfile string +DATA/asm/asmparameterfile/registry.253.707737977

6. Restart HAS stack

crsctl stop has
crsctl start has

7. Add components back to Oracle Restart Configuration

If you had the database, listener and other components, add them back to the Oracle Restart Configuration.

7.1. Add database component

This step should be performed as RDBMS owner (oracle user).

srvctl add database -d <db_unique_name> -o <oracle_home>

7.2. Add listener component

This step should be performed as Grid Infrastructure owner (grid user).

srvctl add listener

7.3. Add other components

For information on how to add back additional components, please review:

Oracle Database Administrator's Guide 11g Release 2 (11.2)

Chapter 4 Configuring Automatic Restart of an Oracle Database

Section Configuring Oracle Restart