Time for action – starting the physical standby instance and making it ready for the RMAN duplicate

Execute the following steps to start a database instance on the standby server and make it ready for the RMAN duplicate operation.

  1. Create a service in Windows.

    If you are creating a Data Guard configuration in Windows, you must create a service using the oradim utility as follows:

    oradim -NEW -SID <sid> -STARTMODE manual -PFILE C:\app\oracle\product\11.2.0\admin\<sid>\pfile\init.ora

    You can skip this step if the environment is not Windows.

  2. Set the standby database initialization parameters:

    Copy the PFILE from the primary system to the standby system under the $ORACLE_HOME/dbs directory with the proper name (initINDIA.ora in our example). Make changes as needed if the control file locations will be different on the standby database and then change locations. The diagnostic destination and memory must be checked. You also need to set the standby-related parameters we've just covered. Use the following example to compare parameters of the primary and standby databases.

    We haven't set Data-Guard-related parameters on the primary database yet. We'll set them after the RMAN duplicate operation finishes successfully. The following primary initialization parameters will be the final status.

    Note

    In this example, the database files on the primary database are under the /u01 directory and the database files on the standby database are under the /u02 directory. This has been configured intentionally to show you the settings of the related initialization parameters.

    The following are the primary database parameters:

    control_files='/u01/app/oracle/oradata/orcl/control01.ctl','/u01/app/oracle/flash_recovery_area/orcl/control02.ctl'
db_name='orcl'
db_file_name_convert='/u02/app/oracle/oradata/orcl','/u01/app/oracle/oradata/orcl' # for switchover purpose
db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
db_recovery_file_dest_size=4070572032
db_unique_name='turkey_un'
diagnostic_dest='/u01/app/oracle'
fal_server='INDIA' # for switchover purpose
instance_name='TURKEY'
local_listener='LISTENER'
log_archive_dest_1='LOCATION=USE_DB_RECOVERY_FILE_DEST VALID_FOR=(ALL_LOGFILES,ALL_ROLES)'
log_archive_dest_2='SERVICE=INDIA LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=INDIA_UN' 
log_archive_config='DG_CONFIG=(turkey_un,india_un)'
log_archive_max_processes=8
log_file_name_convert='/u02/app/oracle/oradata/orcl','/u01/app/oracle/oradata/orcl' # for switchover purpose 
memory_target=822083584
remote_login_passwordfile='EXCLUSIVE'
standby_file_management='AUTO' # for switchover purpose

    The following are the standby database parameters:

    control_files='/u02/app/oracle/oradata/orcl/control01.ctl','/u02/app/oracle/flash_recovery_area/orcl/control02.ctl'
db_name='orcl'
db_file_name_convert='/u01/app/oracle/oradata/orcl','/u02/app/oracle/oradata/orcl'
db_recovery_file_dest='/u02/app/oracle/flash_recovery_area'
db_recovery_file_dest_size=4070572032
db_unique_name='india_un'
diagnostic_dest='/u02/app/oracle'
fal_server='TURKEY'
instance_name='INDIA'
local_listener='LISTENER'
log_archive_dest_1='LOCATION=USE_DB_RECOVERY_FILE_DEST VALID_FOR=(ALL_LOGFILES,ALL_ROLES)'
log_archive_dest_2='SERVICE=TURKEY LGWR ASYNC VALID_FOR= (ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=turkey_un' # for switchover purpose
log_archive_config='DG_CONFIG=(turkey_un,india_un)'
log_archive_max_processes=8
log_file_name_convert='/u01/app/oracle/oradata/orcl','/u02/app/oracle/oradata/orcl'
memory_target=822083584
remote_login_passwordfile='EXCLUSIVE'
standby_file_management='AUTO'
  3. After preparing the standby instance parameter file, set the Oracle user environment variables and start the standby instance in the No Mount status. 
    [oracle@oracle-stby ~]$ export ORACLE_HOME= /u01/app/oracle/product/11.2.0/db_1
[oracle@oracle-stby ~]$ export ORACLE_SID=INDIA
[oracle@oracle-stby ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Sun Aug 12 12:17:01 2012
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.

SQL>startup nomount
ORACLE instance started.
Total System Global Area 818401280 bytes
Fixed Size 2217792 bytes
Variable Size 507513024 bytes
Database Buffers 306184192 bytes
Redo Buffers 2486272 bytes

SQL> select host_name,status from v$instance;
HOST_NAME STATUS
-------------------- ------------
oracle-stby STARTED
  4. The following are the SQL*Net configurations.

    With 11g, we can use RMAN duplicate without the need of primary database backup. The RMAN duplicate using the active database feature reads from the original database files. In order to use this feature, we have to perform static registration of the service to the listener. To do this, we configure both the listener and TNS names. The standby database instance must be in the NOMOUNT state before the duplicate command. In the NOMOUNT state, the database instance will not self-register with the listener. Another item to note is that you must use a dedicated server to connect when the database is in the NOMOUNT state.

    Before we jump into configuration, let's describe static service information. Static service information is normally not required in the listener.ora configuration file. In order to perform duplicate using active database to connect instance in NOMOUNT status, we are using static listener entry. The parameters required for static service information are SID_NAME, GLOBAL_DBNAME, and ORACLE_HOME.

    • SID_NAME: The Oracle SID is the instance identifier, as in the INSTANCE_NAME parameter of the parameter file
    • GLOBAL_DBNAME: The GLOBAL_DBNAME parameter is typically a concatenation of the DB_DOMAIN and DB_NAME parameters in the parameter file or the same as the SERVICE_NAMES parameter in the parameter file
    • ORACLE_HOME: It's the installation directory of the Oracle database software

    Configure the listener and TNS configuration on both the primary and standby databases. The following is the example of the standby database's listener.ora configuration:

    LISTENER=
 (DESCRIPTION=
 (ADDRESS_LIST=
 (ADDRESS=(PROTOCOL=tcp) (HOST= oracle-stby)(PORT=1521)) 
 (ADDRESS=(PROTOCOL=ipc)(KEY=extproc))))
SID_LIST_LISTENER =
 (SID_LIST =
 (SID_DESC =
 (SID_NAME = PLSExtProc)
 (ORACLE_HOME = /u01/app/oracle/product/11.2.0/db_1)
 (PROGRAM = extproc))
 (SID_DESC =
 (GLOBAL_DBNAME = india_un)
 (SID_NAME = INDIA)
 (ORACLE_HOME = /u01/app/oracle/product/11.2.0/db_1)))

    The following will be the TNS entry primary database used to connect the standby database:

    INDIA =
 (DESCRIPTION =
 (ADDRESS = (PROTOCOL = TCP)(HOST = oracle-stby)(PORT = 1521))
 (CONNECT_DATA =
 (SERVER = DEDICATED)
 (SERVICE_NAME = india_un)))
    Tip

    PMON automatically registers with the listener listening on the default port, 1521. If the listener is listening from a non-default port, or if this is an RAC database, the LOCAL_LISTENER parameter must be set to register PMON with the listener. Set the LOCAL_LISTENER parameter to the local listener alias, the name of the listener in the listener.ora file. Also, the LOCAL_LISTENER value has to be resolved using the tnsnames.ora file or in an Oracle Names Server.

  5. Now start the listeners on both the primary and standby servers. 
    $lsnrctl start

    When the listener is running, check the database accessibility and response time, using tnsping from both primary to standby and standby to primary databases.

    The registered services with the listener of primary should be similar to the following screenshot:

    The registered services with the listener of standby are as follows:

  6. Copy the password file from the primary system to standby. You can find this file under the $ORACLE_HOME/dbs directory with the name orapwSID. Copy it to the same directory on the standby server and rename correspondingly.
  7. If you have configured the encryption wallet on the primary database, copy the wallet to the standby system. If you have more than one standby database, you must copy these files to every standby location. You can access the encrypted data from standby when the wallet module contains the master encryption key from the primary database.

What just happened?

We're ready to start the RMAN duplicate. Let's revisit the actions that have been performed on the primary and standby systems:

Using RMAN duplicate to create physical standby databases

In order to create a physical standby database, we have several methods depending on the release features. We've already mentioned that we'll use the RMAN duplicate from the active database method. In this method, there's no need to take a backup in primary and copy it on the standby system.

Here is an overview of the other methods used to create a standby database:

  • Hot backups: Backups taken from the primary database by executing the ALTER DATABASE BEGIN BACKUP command can be used to create a standby database.
  • RMAN backups: Full (level 0) RMAN database backups can also be used for the standby configuration.
  • Cloud Control: This is the only graphical interface we can use to create a standby database configuration. It offers online duplicates, existing or new RMAN backups, and handles the steps of copying the init.ora file and the password file.
Tip

For the first two methods, all the preconfigurations we've set until now are still needed.

When creating the active database duplicate, RMAN copies the datafiles directly from the primary database to the standby database over the network; in such cases, the primary database must be opened or mounted. Before we start creating the RMAN duplicate, we start the standby instance in the NOMOUNT status; after successful duplication, RMAN leaves the instance in the MOUNT status.

上一章目录下一章