1.PRIMARY
原來的主庫，新增新備庫的配置信息。
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
第一套備庫調整配置信息。
SQL> alter system set LOG_ARCHIVE_CONFIG='DG_CONFIG=(ORA11G_PRIM,ORA11G_STBY,ORA11G_STBY2)';
3.SECOND STANDBY
配置第二套備庫。由於第一套備庫和第二套備庫在同一臺物理機上，因此需要注意目錄隔離，避免新備庫破壞就備庫的文件。
3.1 參數文件
[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/'
通過參數文件啓動新備庫到nomount狀態
[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 網絡配置
[oracle@oradb2 dbs]$ cd $ORACLE_HOME/network/admin
[oracle@oradb2 admin]$ vi listener.ora
新增新備庫的配置信息，註冊到靜態監聽中。
(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)
)
重啓監聽，使配置生效，檢查所有配置的靜態監聽生效
[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...
新增新備庫tns配置信息。
[oracle@oradb2 admin]$ vi tnsnames.ora [主庫也需要新增該配置]
ORA11G_STBY2 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = oradb2)(PORT = 1521))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = ORA11G_STBY2)
)
)
3.4 測試數據庫連接 [主庫和新備庫都需要進行測試]
[oracle@oradb2 ~]$ sqlplus sys/oracle@ORA11G_STBY2 as sysdba
[oracle@oradb2 ~]$ sqlplus sys/oracle@ORA11G_PRIM as sysdba
3.5 新備庫進行復制主庫操作
注意此處連接到新的備庫。
[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 啓動新備庫數據庫並啓動實時恢復
[oracle@oradb2 ~]$ export ORACLE_SID=ora11g2
SQL> alter database open;
SQL> alter database recover managed standby database using current logfile disconnect from session;
4.將新備庫添加到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. 進行主備切換操作
通過DG Broker管理的DG環境，在進行主備切換過程中，參數會自動進行維護，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';
切記在switchover時，使用用戶名和口令連接到dgmgrl，否則會造成切換後，無法啓動遠程數據庫，導致切換失敗。