2 Oracle Data Guard Installation

This chapter includes the following topics:

Oracle Data Guard Installation
Prerequisites for First Use

See Also:
Appendix B for help with upgrading the Oracle databases and Oracle Enterprise Manager in a Data Guard broker configuration

2.1 Oracle Data Guard Installation

Oracle Data Guard is included with the Enterprise Edition and Personal Edition of the Oracle database software. A Data Guard configuration may be managed by using either SQL*Plus, or Data Guard broker's command-line interface (DGMGRL), or Oracle Enterprise Manager 10g Grid Control.

To use DGMGRL, the best practice is to install the Oracle Enterprise Edition or Personal Edition database software on each location you expect to include in broker configurations. You must install Oracle Enterprise Manager 10g Grid Control to use the Enterprise Manager Web-based user interface for Data Guard.

In addition, to use fast-start failover you must install DGMGRL and run the observer software on a computer system that is separate from the primary and standby systems. To install DGMGRL on the observer computer, use one of the methods described in the following list:

Install the complete Oracle Client Administrator by choosing the Administrator option from Oracle Universal Installer.

This installation includes DGMGRL but it does not include the Oracle Enterprise Manager agent. This allows you to manage the observer using DGMGRL commands but not Oracle Enterprise Manager.
Install the full Oracle Database 10g software kit.

This installation includes DGMGRL and the Oracle Enterprise Manager agent, allowing you to manage the observer using Oracle Enterprise Manager or DGMGRL commands.

Note:
The operating system on the observer computer can be different from the operating system running on the primary computer or target standby database computer. However, the operating system for the primary database computer and all associated standby database computers must be the same.

2.2 Prerequisites for First Use

The following conditions must be true before you can use the broker:

The primary and standby databases must be running Oracle Database 10g (10.2) and each can be installed in either a single-instance or multi-instance environment. The database must be licensed for Oracle Enterprise Edition or Personal Edition.
You must use a server parameter file (SPFILE) to ensure the broker can persistently reconcile values between broker properties and any related initialization parameter values. See Section 4.3.2 for more information.
The value of the DG_BROKER_START parameter must be set to TRUE. See Section 3.3 for more information. (Enterprise Manager sets this parameter automatically.)
If any of the databases in the configuration is a RAC database, you must set up the DG_BROKER_CONFIG_FILEn initialization parameters for that database such that they point to the same shared files for all instances of that database. The shared files could be files on a cluster file system, if available, on raw devices, or stored using A utomatic Storage Management (ASM).

See Also:
Configuration file information in Section 1.6.2. Section 3.2 for details about setting up the broker configuration file, and Section 3.2.2.2 for details about sizing the raw devices.
Oracle Net Services network files must be set up on the primary database and on the standby database if you configure an existing standby database into the broker configuration. Otherwise, Enterprise Manager automatically sets up the network files when it creates a standby database.
If you are using a nondefault port number (for example, something other than port 1521) for the local listener address, you must set the LOCAL_LISTENER initialization parameter on each instance that is part of a broker configuration to a listener address that is reachable by all members of the configuration. See the Oracle Database Reference and the Oracle Database Net Services Administrator's Guide for additional information.
To enable DGMGRL to restart instances during the course of broker operations, a service with a specific name must be statically registered with the local listener of each instance. The value for the GLOBAL_DBNAME attribute must be set to a concatenation of db_unique_name_DGMGRL.db_domain. For example, in the LISTENER.ORA file:
```
LISTENER = (DESCRIPTION = 
     (ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=host_name)
     (PORT=port_num))))
SID_LIST_LISTENER=(SID_LIST=(SID_DESC=(SID_NAME=sid_name)
     (GLOBAL_DBNAME=db_unique_name_DGMGRL.db_domain)
     (ORACLE_HOME=oracle_home)))
```
Any database, including instances of the database, managed by the broker must be mounted.
If any of the databases in the configuration is a RAC database, the START_OPTIONS for that database must be set to MOUNT in the Oracle Cluster Repository (OCR) using srvctl as follows:
```
srvctl add database -d <db_unique_name> -o <$oracle_home> -s mount
or
srvctl modify database -d <db_unique_name> -o <$oracle_home> -s mount
```
The primary database must be opened in ARCHIVELOG mode.
You must set the COMPATIBLE initialization parameter to 9.2.0.1.0 or higher for both the primary and standby databases. However, if you want to take advantage of new Oracle Database 10g features, set the COMPATIBLE parameter to 10.2.0.0.

Ensure the COMPATIBLE initialization parameter is set to the same value on both the primary and standby databases. If the values differ, redo transport services may be unable to transmit redo data from the primary database to the standby databases.

See Also:
Section 3.3 for more information about preparing and starting the Oracle Data Guard broker. See Oracle Data Guard Concepts and Administration for more information about setting up the network files.