11 Creating RAC Databases with the Database Configuration Assistant

Using the Database Configuration Assistant in Real Application Clusters

The primary functions of the DBCA processing include:

• Create the database and its instances

• Set up network configuration for database, instances and database services

• Invoke EMCP and set up targets.xml file for Enterprise Manager Grid Control of the database

• Start up database, its instances, services, and any other node applications

  
  

  See Also: "Creating the Database after Installation Using the Database Configuration Assistant" for more information about using the DBCA in standalone mode The Oracle Net Services Administrator's Guide if you experience problems, for example, with the listener configuration, and for further information about Lightweight Directory Access Protocol (LDAP)-compliant directory support

Benefits of Using the Database Configuration Assistant

Oracle recommends that you use the DBCA to create your RAC database because the DBCA's preconfigured databases optimize your environment for features such as ASM, the server parameter file, and automatic undo management. The DBCA also provides pages to create new ASM disk groups if they are needed and configures recovery and backup disk space if you are using ASM or cluster file system storage.

With the DBCA, you may create site-specific tablespaces as part of database creation. If you have datafile requirements that differ from those offered by the DBCA templates, then create your database with the DBCA and modify the datafiles later. You can also execute user-specified scripts as part of your database creation process.

The DBCA also configures your RAC environment for various Oracle high availability features such as services and cluster administration tools. It also starts any database instances required to support your defined configuration.

Real Application Clusters High Availability Services

When you configure high availability services with the DBCA Database Services page, you can also configure service instance preferences and Transparent Application Failover (TAF) policies.

Creating the Database after Installation Using the Database Configuration Assistant

To create a database with the DBCA in standalone mode without ASM or a cluster file system, you must have configured each raw device as described in Appendix C. In addition, you must have run the Oracle Net Configuration Assistant to configure your Oracle Net listener.ora file.

On Windows-based systems, if you plan to use ASM storage, then you must have created logical partitions without primary partitions on the same drive and deleted the drive letters for these partitions on all nodes or stamped these partitions with asmtool.

If you select DBCA templates that use preconfigured datafiles and if you do not use ASM or a cluster file system, then during database creation the DBCA first verifies that you created the raw devices for each tablespace. If you have not configured the raw devices, then you must configure the raw devices and replace the default datafile names that the DBCA provides with raw device names on the DBCA Storage page to continue database creation.

To start the DBCA, connect to one of your nodes with Oracle RAC installed and then:

• On UNIX-based platforms, enter the DBCA command from the $ORACLE_HOME/bin directory

• On Windows-based platforms, choose Start > Programs > Oracle - [HOME_NAME] Configuration and Migration Tools > Database Configuration Assistant

Creating a Real Application Clusters Database with the DBCA

The first page that the DBCA displays is the Welcome page for RAC. The DBCA displays this RAC-specific Welcome page only if the Oracle home from which it is invoked was cluster installed.

If the DBCA does not display the Welcome page for RAC, then the DBCA was unable to detect whether the Oracle home is cluster installed. In this case, check that the OUI inventory is correctly located in /var/opt/oracle/oraInst.loc and that oraInventory is not corrupted. Also, perform clusterware diagnostics by executing the olsnodes command from the bin directory in CRS home. Otherwise, to create a RAC database:

1. Select Create a database and click Next, and the DBCA displays the Node Selection page.

2. The DBCA highlights the local node by default. Select the other nodes that you want to configure as members of your cluster database, click Next, and the DBCA displays the Database Templates page. If nodes that are part of your cluster installation do not appear on the Node Selection page, then perform inventory diagnostics and the clusterware diagnostics by executing the olsnodes command.

3. The templates on the Database Templates page are Custom Database, Transaction Processing, Data Warehouse, and General Purpose. The Custom Database template does not include datafiles or options specially configured for a particular type of application. Use one of the other templates, which include datafiles, if you want to create database with specifically configured options. Select the template from which you wish to create your cluster database, click Next, and the DBCA displays the Database Identification page.

4. Enter the global database name and the Oracle system identifier (SID) prefix for your cluster database, click Next, and the DBCA displays the Management Options page.

   
   

   Note: The global database name can be up to 30 characters in length and must begin with an alphabetical character. The SID prefix must begin with an alphabetical character and contain no more than 5 characters on UNIX-based systems or 61 characters on Windows-based systems. The DBCA uses the SID prefix to generate a unique value for the ORACLE_SID for each instance.

5. On the Management Options page, you can choose to manage your database with Enterprise Manager. On UNIX-based systems only, you can also choose either the Grid Control or Database Control option if you select Enterprise Manager database management. If you select Enterprise Manager with the Grid Control option and DBCA discovers agents running on the local node, then you can select the preferred agent from a list.

   If you are on a Windows system or if you select the Database Control option on a UNIX server, then you can set up e-mail notification and enable daily backups. For e-mail notifications, you provide the outgoing mail server and e-mail address. For daily backups, you enter the backup time and OS credentials for the user that takes backup.

   After you make your selections and enter any required information, click Next, and the DBCA displays the Database Credentials page.

6. Enter the passwords for your database on the Database Credentials page. You can enter the same or different passwords for the users SYS and SYSTEM, plus DBSNMP and SYSMAN if you selected Enterprise Manager on the Management Options page. Select the Use the Same Password for All Accounts option to assign the same password to the listed users. Or provide a different password for each of these users by selecting the Use different Passwords option. Enter the password information, click Next, and DBCA displays the Storage Options page.

7. Use the Storage Options page to select a storage type for database creation. The Cluster File System option is the default. Select a storage option and click Next to proceed to the next page. If you selected Cluster File System, then the next page that appears is the Database File Locations page, described in Step 8. If you select Raw Devices, the next page that appears is the Recovery Configuration page, described in Step 9. If you select Automatic Storage Management (ASM), then provide additional information as follows:

   1. If there is not an ASM instance on any of the cluster nodes, then the DBCA displays the Create ASM Instance page for you, described in Step c. Otherwise the DBCA displays the ASM Disk Groups page, described in Step d.

   2. If an ASM instance exists on the local node, then the DBCA displays a dialog asking you to enter the password for the SYS user for ASM.

   3. To initiate the creation of the required ASM instance, supply the password for the SYS user of the ASM instance. If your Oracle home is installed on cluster file system, then the ASM instance uses an SPFILE, otherwise, you can select either an IFILE or an SPFILE on shared storage for the instances. After you enter the required information, click Next to create the ASM instance. Once the instance is created, DBCA proceeds to the ASM Disk Groups page described in Step d.

   4. From the ASM Disk Groups page, you can create a new disk group, add disks to an existing disk group, or select a disk group for your database storage.

      If you have just created a new ASM instance, then there will be no disk groups from which to select, so you must create a new one by clicking Create New to open the Create Disk Group page, described in Step e.

      Similarly, if one or more disk groups are displayed but you want to add a new one, then click Create New and follow the procedure described in Step e to complete the Create Disk Group page.

      If you want to use an existing disk group but wish to add more disks to it, click Add Disks and follow the instructions in Step f.

      Once you are satisfied with the ASM disk groups available to you, select the one you wish to use for your database files and click Next to proceed to the Database File Locations page, described in step 8.

      
      

      Note: To use a flash recovery area, Oracle recommends that you create two separate ASM disk groups: one for the database area and one for the recovery area.

      
      

      See Also: Oracle Database Concepts for more information about using a flash recovery area

   5. Enter the disk group name and then click the redundancy level for the group if you do not wish to use the default value (Normal). Create your disk group by selecting from the list of candidate disks. Continue by following the process described in Step g.

   6. If there is a disk group that you want to use but you want to add more disks to it, then select the group and click Add Disks. Add to the disk group by selecting from the list of candidate disks. Continue by following the process described in Step g.

   7. If you do not see the disks you wish to add, click Change Disk Discovery Path to alter the search path used by DBCA to find available disks. You can select disks with a status of Candidate or Former (never used in an ASM disk group or no longer in a group) by checking the select box. If you select a disk with a Member status, you must also check the Force column to confirm that you want the DBCA to remove the disk from its current ASM disk group. When you have selected the desired disks, click OK to add them to your disk group and return to the ASM Disk Groups Page. To proceed, see the instructions described earlier in Step d.

   8. If the DBCA displays the following message:

      The file oracle_home/bin/oracle does not exist on nodes node_list. 
      Make sure that file exists on these nodes before proceeding.
      
      

      then the Oracle home from which the first ASM instance in the cluster runs is not installed on these cluster nodes. You must extend the ASM Oracle home to these nodes by performing the procedure documented in "Step 4: Adding Nodes at the Oracle RAC Database Layer" in the Oracle Real Application Clusters Administrator's Guide. However, do not perform Step 5 in that section. The OUI extends the ASM Oracle home to the selected nodes and performs any configuration required for running an ASM instance on these nodes.

   9. If the DBCA displays the message Please run the DBCA from one of the nodes that has an existing ASM instance node_list., then you are attempting to create a RAC database using ASM storage and the ASM instance does not exist on the node from which you ran the DBCA. However, ASM instances do exist on the remote nodes that appear in the message node list. In this case, the DBCA cannot clone the existing ASM instance from the remote node to the local node. To correct this, start the DBCA from one of the nodes shown in the node list to create your RAC database using ASM storage. This copies the local node's ASM instance and modifies its parameters and attributes to create ASM instances on the nodes in your cluster that do not have ASM instances.

   10. If the DBCA displays the message ORACLE_BASE for ASM home asm_home does not match the value for database home db_home. Please set ORACLE_BASE to asm_home and restart DBCA., then this means that you selected a node to be part of your RAC database that does not have an ASM instance. In addition, the ASM instance on the local node is running from an Oracle home that is different from the Oracle home for the database to be created. Both the ASM home and the database home must be under a common ORACLE_BASE. If you created the original ASM instance without setting ORACLE_BASE, then set the ORACLE_BASE to the asm_home and restart the DBCA to proceed.

8. The Database File Locations page enables you to select the file storage for your database files: locations provided in a template, a common location for all database files (the files will not be Oracle-managed files), or Oracle-managed files in a common location. If you do not select the template option, you can enter an existing ASM disk group name or directory path name in the space provided, or click Browse to open a selection list.

   If you wish to multiplex the database redo log files and control files, click Multiplex Redo Logs and Control Files and provide the location for each copy you want. Click OK when you have defined the multiplex locations to return to the Database File Locations page.

   You may also define your own variables for the file locations if you plan to use the Database Storage page, explained in Step 13, to define individual file locations.

9. On the Recovery Configuration page, you can select redo log archiving by selecting Enable Archiving. If you are using ASM or CFS storage, then you can also select the flash recovery area and size on the Recovery Configuration page. If you are using ASM, then the flash recovery area defaults to the ASM Disk Group. If you are using CFS, then the flash recovery area defaults to $ORACLE_BASE/flash_recovery_area.

   You may also define your own variables for the file locations if you plan to use the Database Storage page, explained in Step 13, to define individual file locations.

   When you have completed your entries, click Next, and the Database Content page is displayed.

10. On the Database Content page, if you chose the Custom Database option, you can select or deselect the database components and their corresponding tablespace assignment. For a seed database, you can select whether to include the sample schemas in your database and to run custom scripts as part of the database creation processing. After completing your selections, click Next, and the Databases Services page is displayed.

11. To create services on the Database Services page, expand the Services tree. Oracle displays the global database name in the top left-hand corner of the page. Select the global database name and click Add to add services to the database. Enter a service name in the Add a Service dialog and click OK to add the service and return to the Database Services page.

    The service name appears under the global database name. Select the service name and the DBCA displays the service preferences for the service on the right-hand side of the DBCA Database Services page. Change the instance preference (Not Used, Preferred, or Available) and TAF policies for the service as needed.

    Repeat this procedure for each service and when you are done configuring services for your database, click Next. The DBCA displays the Initialization Parameters page.

12. By default, the Initialization Parameters page shows only the basic parameters and only enables you to change the parameter file definition if you are using raw storage. Each tab on the Initialization Parameters page provides different sets of information that you can add or modify as follows:

    1. Memory Tab: Click Typical for default values based on the database type you selected or Custom to set your own values for the memory parameters. You can also see values for the advanced parameters by clicking All Initialization Parameters.

       Carefully review the parameter settings displayed in this dialog because the DBCA configures these settings in your server parameter file. Instance-specific parameter settings for your RAC database appear at the bottom of this dialog. The sid prefixes for these entries appear in the left column.

       To review the instance-specific parameter settings, scroll downward using the scroll bar on the right side of the dialog. Use the check box in the Override Default column to indicate whether the DBCA should place the parameter setting in your server parameter file. The DBCA only places a parameter entry into the server parameter file if the entry displays a check mark in the Override Default column of the All Initialization Parameters dialog.

       
       

       Notes: You cannot modify the sid in the Instance columnYou can alter self-tuning parameters with this dialog. However, setting these parameters to inappropriate values may disable the Oracle self-tuning features.You cannot specify instance-specific values for global parameters with the DBCA. You should set the value of the CLUSTER_DB_INSTANCES parameter to the number of instances you intend to use in the cluster if you are not including all the related nodes during the current execution of DBCA. If your global database name is longer than eight characters, then the database name value (in the db_name parameter) is truncated to the first eight characters and the DB_UNIQUE_NAME parameter value is set to the global name.

    2. Sizing Tab: Use this page to select the database standard block size and process count.

    3. Character Sets Tab: Use this page to set the database character set value.

    4. Connection Mode Tab: You can use this tab to select either dedicated or shared database connections to your database.

    5. Parameter File Tab: This tab will only appear if you are using raw storage. Use this tab to enter a raw device name for the location of the server parameter file.

    When you have completed all your work on the Initialization Parameters page, click Next, and the Database Storage page is displayed.

13. If you selected a preconfigured database template, such as the General Purpose template, then the DBCA displays the control files, datafiles, and redo logs on the Database Storage page. Select the folder and the file name underneath the folder to edit the file name. However, if you selected the Custom Database template, the template without datafiles, then the DBCA displays the control files, tablespaces, datafiles, and redo logs. To change the tablespace properties, such as the datafile or the tablespace size, click the tablespaces icon to expand the object tree on the left-hand side of the page and click the tablespace. The tablespace property dialog appears on the right-hand side. Make your changes and click OK.

    When entering file names in the Database Storage page for raw storage, note the following

    • If you have not set the DBCA_RAW_CONFIG environment variable, then the DBCA displays default datafile names. You must override these names to provide raw device names on this page for each control file, datafile, and redo log group file.

    • For Windows-based platforms, if the default symbolic links exist and you have not set the DBCA_RAW_CONFIG environment variable, then the DBCA replaces the default datafiles with these symbolic link names and displays them in the Database Storage page. If the symbolic links do not exist, then the DBCA displays the default file system datafile file names on the Database Storage page. In this case, replace the default datafile file names with the symbolic link names.

    After you complete your entries on the Database Storage page, click Next, and the DBCA displays the Creation Options page.

14. On the Creation Options page, select one of the following database options and click Finish.

    • Create Database—Creates the database

    • Save as a Database Template—Creates a template that records the database structure, including user-supplied inputs, initialization parameters, and so on. You can later use this template to create a database.

    • Generate Database Creation Scripts—Generates database creation scripts. The DBCA only displays this option if you selected the Custom Database template.

    After you click Finish, the DBCA displays a Summary dialog.

15. Review the Summary dialog information and click OK to create the database.

After you complete Step 15 the DBCA:

• Creates an operative RAC database and its instances

• Creates the RAC data dictionary views

• Configures the network for the cluster database

• Starts the Oracle services if you are on a Windows-based platform

• Starts the listeners and database instances and then starts the high availability services

Deleting a Real Application Clusters Database with the DBCA

This section explains how to delete a RAC database with the DBCA. This process deletes a database and removes a database's initialization parameter files, instances, OFA structure, and Oracle network configuration. However, this process does not remove datafiles if you placed the files on raw devices or on raw partitions.

To delete a database with the DBCA:

1. Start the DBCA on one of the nodes:

   • On UNIX-based platforms, execute the DBCA command from the $ORACLE_HOME/bin directory

   • On Windows-based platforms, choose Start > Programs > Oracle - [HOME_NAME] Configuration and Migration Tools > Database Configuration Assistant

   The DBCA Welcome page appears.

2. Select Oracle Real Application Clusters and click Next.

   After you click Next, the DBCA displays the Operations page.

3. Select Delete a database, click Next, and the DBCA displays the List of Cluster Databases page.

4. If your user ID and password are not operating-system authenticated, then the List of Cluster Databases page displays the user name and password fields. If these fields appear, then enter a user ID and password that has SYSDBA privileges.

   
   

   See Also: "Database Password and Role Management in Real Application Clusters" on page B-19

5. Select the database to delete and click Finish.

   After you click Finish, the DBCA displays a dialog to confirm the database and instances that the DBCA is going to delete.

6. Click OK to begin the deletion of the database and its associated files, services, and environment settings, or click Cancel to stop the operation.

When you click OK, the DBCA continues the operation and deletes all of the associated instances for this database. The DBCA also removes the parameter files, password files, and oratab entries.

At this point, you have accomplished the following:

• Deleted the selected database from the cluster

• Deleted the selected database's Oracle services for Windows-based platforms

• Deleted high availability services that were assigned to the database

• Deleted the Oracle Net configuration for the database

• Deleted the OFA directory structure from the cluster

• Deleted the datafiles if the datafiles were not on raw devices