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

This chapter describes how to extend an existing Oracle Real Application Clusters (Oracle RAC) home to other nodes and instances in the cluster, and delete Oracle RAC from nodes and instances in the cluster. This chapter provides instructions for Linux and UNIX systems.

If your goal is to clone an existing Oracle RAC home to create multiple new Oracle RAC installations across the cluster, then use the cloning procedures that are described in Chapter 6, "Cloning Oracle RAC to Nodes in a Cluster".

The topics in this chapter include the following:

Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Deleting Oracle RAC from a Cluster Node

Note:

The phrase "target node" as used in this chapter refers to the node to which you plan to extend Oracle RAC environment.

See Also:

Oracle Database 2 Day + Real Application Clusters Guide for additional information about configuring a new Oracle RAC cluster or scaling up an existing Oracle RAC cluster

Adding Oracle RAC to Nodes with Oracle Clusterware Installed

Before beginning this procedure, ensure that your existing nodes have the correct path to the Grid_home and that the $ORACLE_HOME environment variables are set correctly.

See Also:

Oracle Clusterware Administration and Deployment Guide for information about adding nodes to a cluster

To add Oracle RAC to nodes that already have Oracle Clusterware installed, you must extend the Oracle RAC home that is on an existing node (node1 in this procedure) of the cluster to the target nodes.

Navigate to the Oracle_home/oui/bin directory on node1 and run the addNode.sh script using the following syntax:
```
$ ./addNode.sh -silent "CLUSTER_NEW_NODES={node2}"
```
Run the root.sh script on node2 as root.
If you store your policy-managed database on Oracle Automatic Storage Management (Oracle ASM), Oracle Managed Files (OMF) is enabled, and if there is space in a server pool for node2, then crsd adds the Oracle RAC instance to node2 and no further action is necessary. If OMF is not enabled, then you must manually add undo and redo logs.

If there is no space in a server pool, then node2 moves into the FREE server pool. Use srvctl modify srvpool to increase the cardinality of the server pool to accommodate node2, after which time node2 moves out of the FREE server pool and into the modified server pool, and crsd adds the Oracle RAC instance to node2.
If you have an administrator-managed database, then add a new instance on node2 as described in "Adding Oracle RAC Database Instances to Target Nodes".

Note:

Oracle recommends that you back up your voting disk and Oracle Cluster Registry (OCR) files after you complete the node addition process.

Adding Oracle RAC Database Instances to Target Nodes

Note:

The procedures in this section only apply to administrator-managed databases. Policy-managed databases use nodes when the nodes are available in the databases' server pool.

You can use either Oracle Enterprise Manager or DBCA to add Oracle RAC database instances to the target nodes. To add a database instance to a target node with Oracle Enterprise Manager, see the Oracle Database 2 Day + Real Application Clusters Guide for complete information.

This section describes using DBCA to add Oracle RAC database instances under the following topics:

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

These tools guide you through the following tasks:

Creating a new database instance on each target node
Creating and configuring high availability components
Creating the Oracle Net configuration for a non-default listener from the Oracle home
Starting the new instance
Creating and starting services if you entered services information on the Services Configuration page

After adding the instances to the target nodes, you should perform any necessary service configuration procedures, as described in Chapter 4, "Introduction to Automatic Workload Management".

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:

Ensure that your existing nodes have the $ORACLE_HOME environment variable set correctly.
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.
Select Oracle Real Application Clusters database, click Next, and DBCA displays the Operations page.
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.
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.
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.
Click Next to add a new instance and DBCA displays the Adding an Instance page.
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.
Enter the services information for the target node's instance, click Next, and DBCA displays the Instance Storage page.
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.
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.
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.
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.
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]
```
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

Table 9-1 Variables in the DBCA Silent Mode Syntax

Variable	Description
`node`	The node on which you want to add (or delete) the instance.
`gdbname`	Global database name.
`instname`	Name of the instance. Provide an instance name only if you want to override the Oracle naming convention for Oracle RAC instance names.
`sysdba`	Name of the Oracle user with `SYSDBA` privileges.
`password`	Password for the `SYSDBA` user.

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

Deleting Oracle RAC from a Cluster Node

To remove Oracle RAC from a cluster node, you must delete the database instance and the Oracle RAC software prior to removing the node from the cluster.

This section includes the following procedures to delete nodes from clusters in an Oracle RAC environment:

Deleting Instances from Oracle RAC Databases
Removing Oracle RAC
Deleting Nodes from the Cluster

Deleting Instances from Oracle RAC Databases

The procedures for deleting instances are different for policy-managed and administrator-managed databases. Alternatively, you can shrink a policy-managed database.

Deleting Policy-Managed Databases

Deleting a policy-managed database involves decreasing the size of the server pool in which a database instance resides. This effectively removes the instance without having to remove the Oracle RAC software from the node or the node from the cluster.

For example, you can delete a policy-managed database by running the following commands on any node in the cluster:

$ srvctl stop instance -d db_unique_name -n node_name
$ srvctl relocate server -n node_name -g Free

The first command stops on the instance on a particular node and the second command moves the node out of its current server pool and into the Free server pool.

See Also:

"Removing Oracle RAC" for information about removing the Oracle RAC software from a node

Deleting Instances from Administrator-Managed Databases

Note:

Before deleting an instance from an Oracle RAC database, use either srvctl or Oracle Enterprise Manager to do the following:

If you have services configured, relocate the services
Modify the services so that each service can run on one of the remaining instances
Ensure that the instance to be removed from an administrator-managed database is neither a preferred nor an available instance of any service

The procedures in this section explain how to use DBCA in interactive or silent mode, to delete an instance from an Oracle RAC database.

See Also:

Oracle Database 2 Day + Real Application Clusters Guide for information about how to delete a database instance from a target node with Oracle Enterprise Manager

This section includes the following topics:

Using DBCA in Interactive Mode to Delete Instances from Nodes
Using DBCA in Silent Mode to Delete Instances from Nodes

Using DBCA in Interactive Mode to Delete Instances from Nodes

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

Verify there is a current backup of the OCR.

Run the ocrconfig -showbackup command to ensure there is a valid backup.
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.
On the DBCA Welcome page select Oracle Real Application Clusters Database, click Next. DBCA displays the Operations page.
On the DBCA Operations page, select Instance Management and click Next. DBCA displays the Instance Management page.
On the DBCA Instance Management page, select the instance to be deleted, select Delete Instance, and click Next.
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.
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;
```
Verify that the instance has been removed from the OCR by running the following command:
```
srvctl config database -d db_unique_name
```
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.

Removing Oracle RAC

This procedure removes Oracle RAC from the node you are deleting from the cluster and updates inventories on the remaining nodes.

If there is a listener in the Oracle RAC home on the node you are deleting, then you must disable and stop it before deleting the Oracle RAC software. Run the following commands on any node in the cluster, specifying the name of the listener and the name of the node you are deleting:
```
$ srvctl disable listener -l listener_name -n name_of_node_to_delete
$ srvctl stop listener -l listener_name -n name_of_node_to_delete
```
Run the following command from $ORACLE_HOME/oui/bin on the node that you are deleting to update the inventory on that node:
```
$ ./runInstaller –updateNodeList ORACLE_HOME=Oracle_home_location
"CLUSTER_NODES={name_of_node_to_delete}" -local
```
Depending on whether you have a shared or nonshared Oracle home, complete one of the following two procedures to remove the Oracle RAC software:
- For a shared home, detach the node instead of deinstalling it by running the following command from the $ORACLE_HOME/oui/bin directory on each of the nodes that you want to delete:
```
$ ./runInstaller -detachHome ORACLE_HOME=Oracle_home_location
```
- For a nonshared home, deinstall the Oracle home from the node that you are deleting by running the following command from the $ORACLE_HOME/deinstall directory:
  
  See Also:
  Oracle Clusterware Administration and Deployment Guide for more information about deleting nodes
```
$ ./deinstall -local
```
Run the following command from the $ORACLE_HOME/oui/bin directory on any one of the remaining nodes in the cluster to update the inventories of those nodes, specifying a comma-delimited list of remaining node names:
```
$ ./runInstaller –updateNodeList ORACLE_HOME=Oracle_home_location
"CLUSTER_NODES={remaining_node_list}"
```

Deleting Nodes from the Cluster

After you delete the instance, you can begin the process of deleting the node from the cluster. You accomplish this by running scripts on the node you want to delete to remove the Oracle Clusterware installation and you run scripts on the remaining nodes to update the node list.

See Also:

Oracle Clusterware Administration and Deployment Guide for information about deleting nodes from the cluster