9 Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems

Using DBCA in Interactive Mode to Add Database Instances to Target Nodes

To add a database instance to a target node with DBCA in interactive mode, perform the following steps:

1. Ensure that your existing nodes have the $ORACLE_HOME environment variable set correctly.

2. Start DBCA by entering dbca at the system prompt from the Oracle_home/bin directory.

   DBCA performs certain CVU checks while running. However, you can also run CVU from the command line to verify that the Oracle ASM instance is ready for addition to a node, as follows:

   cluvfy stage -pre storadd –s path [-t asm] [-verbose]
   

   Replace path with the directory path by which Oracle ASM is identified within the system.

   See Also:

   Oracle Clusterware Administration and Deployment Guide for more information about CVU

   DBCA displays the Welcome page for Oracle RAC. Click Help on any DBCA page for additional information.

3. Select Oracle Real Application Clusters database, click Next, and DBCA displays the Operations page.

4. If your database is administrator-managed, select Instance Management, click Next, and DBCA displays the Instance Management page.

   If your database is policy-managed, then the Instance Management option is not available. To increase the number of database instances, add more nodes to the server pool.

5. Select Add Instance and click Next. DBCA displays the List of Cluster Databases page that shows the databases and their current status, such as ACTIVE, or INACTIVE.

6. From the List of Cluster Databases page, select the active Oracle RAC database to which you want to add an instance. Enter user name and password for the database user that has SYSDBA privileges. Click Next and DBCA displays the List of Cluster Database Instances page showing the names of the existing instances for the Oracle RAC database that you selected.

7. Click Next to add a new instance and DBCA displays the Adding an Instance page.

8. On the Adding an Instance page, enter the instance name in the field at the top of this page if the instance name that DBCA provides does not match your existing instance naming scheme. Then select the target node name from the list, click Next, and DBCA displays the Services Page.

9. Enter the services information for the target node's instance, click Next, and DBCA displays the Instance Storage page.

10. If you are using raw devices or raw partitions, then on the Instance Storage page select the Tablespaces folder and expand it. Select the undo tablespace storage object and a dialog appears on the right-hand side. Change the default data file name to the raw device name for the tablespace.

11. If you are using raw devices or raw partitions or if you want to change the default redo log group file name, then on the Instance Storage page select and expand the Redo Log Groups folder. For each redo log group number that you select, DBCA displays another dialog box.

12. If you are using a cluster file system, then click Finish on the Instance Storage page. If you are using raw devices, then repeat step 11 for all of the other redo log groups, click Finish, and DBCA displays a Summary dialog.

13. Review the information on the Summary dialog and click OK or click Cancel to end the instance addition operation. DBCA displays a progress dialog showing DBCA performing the instance addition operation. When DBCA completes the instance addition operation, DBCA displays a dialog asking whether you want to perform another operation.

14. After you terminate your DBCA session, run the following command to verify the administrative privileges on the target node and obtain detailed information about these privileges where nodelist consists of the target nodes:

    cluvfy comp admprv -o db_config -d oracle_home -n nodelist [-verbose]
    

15. Perform any needed service configuration procedures, as described in Chapter 4, "Introduction to Automatic Workload Management".

Using DBCA in Silent Mode to Add Database Instances to Target Nodes

You can use DBCA in silent mode to add instances to nodes on which you have extended an Oracle Clusterware home and an Oracle Database home. Use the following syntax where password is the password:

dbca -silent -addInstance -nodeList node -gdbName gdbname [-instanceName instname]
 -sysDBAUserName sysdba -sysDBAPassword password

Before you run the dbca command, ensure that you have set the $ORACLE_HOME environment variable correctly on the existing nodes.

Using DBCA in Interactive Mode to Delete Instances from Nodes

To delete an instance using DBCA in interactive mode, perform the following steps:

1. Verify there is a current backup of the OCR.

   Run the ocrconfig -showbackup command to ensure there is a valid backup.

2. Start DBCA.

   Start DBCA on a node other than the node that hosts the instance that you want to delete. The database and the instance that you plan to delete should continue to be started and running during this step.

3. On the DBCA Welcome page select Oracle Real Application Clusters Database, click Next. DBCA displays the Operations page.

4. On the DBCA Operations page, select Instance Management and click Next. DBCA displays the Instance Management page.

5. On the DBCA Instance Management page, select the instance to be deleted, select Delete Instance, and click Next.

6. On the List of Cluster Databases page, select the Oracle RAC database from which to delete the instance, as follows:

   1. On the List of Cluster Database Instances page, DBCA displays the instances that are associated with the Oracle RAC database that you selected and the status of each instance. Select the cluster database from which you will delete the instance.

   2. Enter a user name and password for the database user that has SYSDBA privileges. Click Next.

   3. Click OK on the Confirmation dialog to proceed to delete the instance.

      DBCA displays a progress dialog showing that DBCA is deleting the instance. During this operation, DBCA removes the instance and the instance's Oracle Net configuration. When DBCA completes this operation, DBCA displays a dialog asking whether you want to perform another operation.

      Click No and exit DBCA or click Yes to perform another operation. If you click Yes, then DBCA displays the Operations page.

7. Verify that the dropped instance's redo thread has been removed by querying the V$LOG view. If the redo thread is not disabled, then disable the thread. For example:

   SQL> ALTER DATABASE DISABLE THREAD 2;
   

8. Verify that the instance has been removed from the OCR by running the following command:

   srvctl config database -d db_unique_name
   

9. If you are deleting more than one node, then repeat these steps to delete the instances from all the nodes that you are going to delete.

Using DBCA in Silent Mode to Delete Instances from Nodes

You can use DBCA in silent mode to delete a database instance from a node.

Run the following command, where the variables are the same as those shown in Table 9-1 for the DBCA command to add an instance. Provide a node name only if you are deleting an instance from a node other than the one on where DBCA is running as shown in the following example where password is the password:

dbca -silent -deleteInstance [-nodeList node] -gdbName gdbname -instanceName
 instname -sysDBAUserName sysdba -sysDBAPassword password

At this point, you have accomplished the following:

• Deregistered the selected instance from its associated Oracle Net Services listeners

• Deleted the selected database instance from the instance's configured node

• Removed the Oracle Net configuration

• Deleted the Oracle Flexible Architecture directory structure from the instance's configured node.