1.PRIMARY

    原来的主库，新增新备库的配置信息。

SQL> alter system set log_archive_dest_state_3=defer;

SQL> alter system set LOG_ARCHIVE_CONFIG='DG_CONFIG=(ORA11G_PRIM,ORA11G_STBY,ORA11G_STBY2)';

SQL> alter system set LOG_ARCHIVE_DEST_3='SERVICE=ORA11G_STBY2 ASYNC DELAY=60 VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORA11G_STBY2';

2.FIRST STANDBY

    第一套备库调整配置信息。

SQL> alter system set LOG_ARCHIVE_CONFIG='DG_CONFIG=(ORA11G_PRIM,ORA11G_STBY,ORA11G_STBY2)';

3.SECOND STANDBY

    配置第二套备库。由于第一套备库和第二套备库在同一台物理机上，因此需要注意目录隔离，避免新备库破坏就备库的文件。

3.1 参数文件

[oracle@oradb2 ~]$ export ORACLE_SID=ora11g

SQL> create pfile='/home/oracle/11g2.pfile' from spfile;

[oracle@oradb2 ~]$ vi 11g2.pfile

*.audit_file_dest='/oracle/app/oracle/admin/ora11g2/adump'

*.control_files='/oradata/database/11g/ora11g2/control01.ctl','/oradata/database/11g/ora11g2/control02.ctl'

*.DB_UNIQUE_NAME='ORA11G_STBY2'

*.fal_server='ORA11G_PRIM'

*.LOG_ARCHIVE_CONFIG='DG_CONFIG=(ORA11G_PRIM,ORA11G_STBY,ORA11G_STBY2)'

*.LOG_ARCHIVE_DEST_1='LOCATION=/oradata/archive/11g2 VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=ORA11G_STBY2'

*.LOG_ARCHIVE_DEST_2='SERVICE=ORA11G_PRIM ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORA11G_PRIM'

*.dg_broker_start=false

*.db_file_name_convert='/oradata/database/11g/ora11g/','/oradata/database/11g/ora11g2/'

*.log_file_name_convert='/oradata/database/11g/ora11g/','/oradata/database/11g/ora11g2/'

    通过参数文件启动新备库到nomount状态

[oracle@oradb2 ~]$ export ORACLE_SID=ora11g2

SQL> startup nomount pfile='/home/oracle/11g2.pfile';

SQL> create spfile from pfile='/home/oracle/11g2.pfile';

SQL> startup force nomount;

3.2 口令文件

[oracle@oradb2 ~]$ cd $ORACLE_HOME/dbs

[oracle@oradb2 dbs]$ cp orapwora11g orapwora11g2

3.3 网络配置

[oracle@oradb2 dbs]$ cd $ORACLE_HOME/network/admin

[oracle@oradb2 admin]$ vi listener.ora 

    新增新备库的配置信息，注册到静态监听中。

    (SID_DESC =

      (GLOBAL_DBNAME = ORA11G_STBY2)

      (ORACLE_HOME = /oracle/app/oracle/product/database/11g)

      (SID_NAME = ora11g2)

    ) 

    (SID_DESC =

      (GLOBAL_DBNAME = ORA11G_STBY2_DGMGRL)

      (ORACLE_HOME = /oracle/app/oracle/product/database/11g)

      (SID_NAME = ora11g2)

    ) 

    重启监听，使配置生效，检查所有配置的静态监听生效

[oracle@oradb2 ~]$ lsnrctl stop

[oracle@oradb2 ~]$ lsnrctl start

[oracle@oradb2 ~]$ lsnrctl status

Services Summary...

Service "ORA11G_STBY" has 2 instance(s).

  Instance "ora11g", status UNKNOWN, has 1 handler(s) for this service...

Service "ORA11G_STBY2" has 2 instance(s).

  Instance "ora11g2", status UNKNOWN, has 1 handler(s) for this service...

Service "ORA11G_STBY2_DGMGRL" has 1 instance(s).

  Instance "ora11g2", status UNKNOWN, has 1 handler(s) for this service...

Service "ORA11G_STBY_DGMGRL" has 1 instance(s).

  Instance "ora11g", status UNKNOWN, has 1 handler(s) for this service...

    新增新备库tns配置信息。

[oracle@oradb2 admin]$ vi tnsnames.ora [主库也需要新增该配置]

ORA11G_STBY2 =

  (DESCRIPTION =

    (ADDRESS_LIST =

      (ADDRESS = (PROTOCOL = TCP)(HOST = oradb2)(PORT = 1521))

    )

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SERVICE_NAME = ORA11G_STBY2)

    )

  )

3.4 测试数据库连接 [主库和新备库都需要进行测试]

[oracle@oradb2 ~]$ sqlplus sys/oracle@ORA11G_STBY2 as sysdba

[oracle@oradb2 ~]$ sqlplus sys/oracle@ORA11G_PRIM as sysdba    

3.5 新备库进行复制主库操作

    注意此处连接到新的备库。

[oracle@oradb2 ~]$ export NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS';

[oracle@oradb2 ~]$ rman target sys/oracle@ORA11G_PRIM auxiliary sys/oracle@ORA11G_STBY2

RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 4;

RMAN> DUPLICATE TARGET DATABASE FOR STANDBY FROM ACTIVE DATABASE DORECOVER NOFILENAMECHECK;

3.6 启动新备库数据库并启动实时恢复

[oracle@oradb2 ~]$ export ORACLE_SID=ora11g2

SQL> alter database open;

SQL> alter database recover managed standby database using current logfile disconnect from session;

4.将新备库添加到dg broker中

[oracle@oradb2 ~]$ export ORACLE_SID=ora11g2

SQL> alter system set dg_broker_start=true;

[oracle@oradb2 ~]$ dgmgrl /

DGMGRL> show configuration;

DGMGRL> ADD DATABASE 'ORA11G_STBY2' AS CONNECT IDENTIFIER IS 'ORA11G_STBY2' MAINTAINED AS PHYSICAL;

DGMGRL> ENABLE DATABASE 'ORA11G_STBY2';

5. 进行主备切换操作

    通过DG Broker管理的DG环境，在进行主备切换过程中，参数会自动进行维护，例如fal_server，log_archive_dest_2，log_archive_dest_3等。

DGMGRL> show configuration;

Configuration - ora11g_dg

  Protection Mode: MaxPerformance

  Databases:

    ORA11G_PRIM  - Primary database

    ORA11G_STBY  - Physical standby database

    ORA11G_STBY2 - Physical standby database

DGMGRL> connect sys/oracle@ORA11G_STBY

DGMGRL> SWITCHOVER TO 'ORA11G_STBY';

    切记在switchover时，使用用户名和口令连接到dgmgrl，否则会造成切换后，无法启动远程数据库，导致切换失败。