2 Oracle Data Guard Installation

2.1 Oracle Data Guard Installation

Oracle Data Guard is included with the Enterprise Edition and Personal Edition of the Oracle database software. You can manage a Data Guard configuration by using either SQL*Plus, the Data Guard broker's command-line interface (DGMGRL), or a compatible version of Oracle Enterprise Manager 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 a compatible version of Oracle Enterprise Manager 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. Oracle recommends running the observer 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. (The Oracle Enterprise Manager agent can be installed separately.)

• Install the full Oracle Database 11g 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 observer can be run from any platform that supports it, and that platform can be different from the platform of the primary or target standby database.

2.2 Prerequisites

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

• The primary and standby databases must be using the same version of Oracle Database 11g 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 initialization 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 an Oracle 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 Automatic Storage Management (ASM).

  See Also:

  Configuration file information in Section 1.6.2. Also, see Section 3.2 for details about setting up the broker configuration file, and Section 3.2.2.3 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. Enterprise Manager can assist you in creating the network files when creating a standby database.

• The connect identifier that you specify for each database in a broker configuration, using the DGConnectIdentifier property, must:

  • Allow all other databases in the configuration to reach it.

  • Allow all instances of an Oracle RAC database to be reached.

  • Specify a service that all instances dynamically register with the listeners so that connect-time failover on an Oracle RAC database is possible.

  • Have failover attributes set to allow the primary database's Redo Transport Services to continue shipping redo data to an Oracle RAC standby database, even if the receiving instance of that standby database has failed.

• 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. A static service registration is also required to enable the observer to restart instances as part of automatic reinstatement of the old primary database after a fast-start failover has occurred. The broker uses a default name for the GLOBAL_DBNAME attribute 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)))
  

  Alternatively, you can use a different static service name. If you do, be sure to modify the StaticConnectIdentifier instance-specific property to reflect the different service name.

• The primary database must be opened in ARCHIVELOG mode.

• You must set the COMPATIBLE initialization parameter to 10.2.0.1.0 or higher for both the primary and standby databases. However, if you want to take advantage of new Oracle Database 11.2 features, set the COMPATIBLE parameter to 11.2.0 on all databases within the Data Guard configuration.

  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.

• Select and configure a redo transport authentication method, as described in Oracle Data Guard Concepts and Administration.