上一篇时候，我们已经安装好了一台DB，接下来开始做DG配置，

DB参数规划
HOSTNAME	IP	DB_NAME	DB_UNIQUE_NAME	INSTANCE_NAME	SERVICE_NAME
mydb01	192.168.110.138	orcl	dbprimary	orcl	orcl
mydb02	192.168.110.139	orcl	dbstandby	orcl	orcl

文件物理路径
文件类别	主库	备库
datafile	/data/oracle/oradata/orcl/	/data/oracle/oradata/orcl/
controlfile	/data/oracle/oradata/orcl/	/data/oracle/oradata/orcl/
archivelog	/data/oracle/oradata/archive/	/data/oracle/oradata/archive/

（一）、主备库上分别配置监听和tns.ora

配置lisenter.ora，內容如下：
   dbprimary的listener.ora (/data/oracle/product/11.2.0/db_1/network/admin目录下):
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = orcl)
      (ORACLE_HOME = /data/oracle/product/11.2.0/db_1)
      (GLOBAL_DBNAME = orcl)
    )
  )
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = mydb01)(PORT = 1521))
    )
  )

   dbstandby的listener.ora:
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = ZZKPHMDB)
      (ORACLE_HOME = /data/oracle/product/11.2.0/db_1)
      (GLOBAL_DBNAME = orcl)
    )
  )
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = mydb02)(PORT = 1521))
    )
  )

  dbprimary和dbstandby上的tnsnames.ora是一样的
# Generated by Oracle configuration tools.

dbprimary =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = mydb01)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )
dbstandby =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = mydb02)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

（二）、检查配置主备库是否正确
 
 备库上执行：oracle>sqlplus sys/oracle@dbprimary as sysdba
 主库上执行：oracle>sqlplus sys/oracle@dbstandby as sysdba

能连上说明主备库可以互通。

（三）、主库上增加standby_log

配置Standby Redo Log。创建组数至少要比主库的online redo log组数多一个。主库增加group 5，6，7；因为会把主库的oradata覆盖掉备库的oradata目录，所以暂时不增加备库的standby_log。查看standby_log:select * from v$standby_log，查看log文件：select * from v$logfile; 过会儿把主库的文件复制到备库后，再在备库上shutdown->startup mount->创建group 8.
alter database add standby logfile group 5 ('/data/oracle/oradata/orcl/redo05.log') size 50m;
alter database add standby logfile group 6 ('/data/oracle/oradata/orcl/redo06.log') size 50m;
alter database add standby logfile group 7 ('/data/oracle/oradata/orcl/redo07.log') size 50m;

4.、dbprimary上配置
1. oracle>mkdir /data/oracle/oradata/archive
2. cd /data/oracle/product/11.2.0/db_1/dbs
   oracle>orapwd file=orapworcl password=oracle entries=4 产生密码文件，也要复制到备库
3. oracle>sqlplus sys as sysdba
 sql>create pfile from spfile; 在/data/oracle/product/11.2.0/db_1/dbs/下生成initorcl.ora
 在initorcl.ora文件后面增加内容：
*.DB_UNIQUE_NAME='dbprimary'
*.LOG_ARCHIVE_CONFIG='DG_CONFIG=(dbprimary, dbstandby)'
*.LOG_ARCHIVE_DEST_1='LOCATION=/data/oracle/oradata/archive VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=dbprimary'
*.LOG_ARCHIVE_DEST_2='SERVICE=dbstandby LGWR SYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=dbstandby'
*.LOG_ARCHIVE_DEST_STATE_1='ENABLE'
*.LOG_ARCHIVE_DEST_STATE_2='ENABLE'
*.LOG_ARCHIVE_FORMAT='%t_%s_%r.arc'
*.LOG_ARCHIVE_MAX_PROCESSES=5
*.FAL_SERVER='dbstandby'
*.FAL_CLIENT='dbprimary'
*.STANDBY_FILE_MANAGEMENT='AUTO'

4. 
 sql>shutdown immediate;
 sql>create spfile from pfile;
 sql>startup mount;
 sql>alter database archivelog;
 sql>alter database open;
 sql>archive log list; 查看是否处于log模式,如果不是执行如下命令
 sql>alter database force logging; 改变为logging模式
 sql>alter database create standby controlfile as '/data/oracle/oradata/orcl/standby01.ctl'; 创建dbstandby上的控制文件
 sql>shutdown immediate;#关闭主库准备打包复制文件
 
5. 把/data/oracle/oradata打包传到dbstandby服务器, 把 /data/oracle/product/11.2.0/db_1/dbs/orapworcl也传过去。复制资料时候主库是关闭状态，待备库配置完成，并启动后，主库再开启。
oracle>cd /data/oracle/
oracle>tar czvf oradata.tar oradata #打包：
oracle>scp /data/oracle/oradata.tar mydb02:/data/app/oracle/
oracle>scp /data/oracle/product/11.2.0/db_1/dbs/orapworcl mydb02:/data/oracle/product/11.2.0/db_1/dbs/

（四）、dbstandby上配置
1. oracle>sqlplus sys as sysdba
   sql>shutdown immediate;
2. oracle>cd /data/app/oracle
   oracle>rm -rf oradata
   把刚才传过来的包解压
   oracle>tar zxvf oradata.tar
   oracle>cd oradata/orcl/
   oracle>cp standby01.ctl standby02.ctl
   oracle>cp standby01.ctl standby03.ctl
3. sql>create pfile from spfile
   修改initorcl.ora
*.control_files='/data/oracle/oradata/orcl/standby01.ctl','/data/oracle/oradata/orcl/standby02.ctl','/data/oracle/oradata/orcl/standby03.ctl'
*.DB_UNIQUE_NAME='dbstandby'
*.LOG_ARCHIVE_CONFIG='DG_CONFIG=(dbprimary, dbstandby)'
*.LOG_ARCHIVE_DEST_1='LOCATION=/data/oracle/oradata/archive/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=dbstandby'
*.LOG_ARCHIVE_DEST_2='SERVICE=dbprimary LGWR SYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=dbprimary'
*.LOG_ARCHIVE_DEST_STATE_1='ENABLE'
*.LOG_ARCHIVE_DEST_STATE_2='ENABLE'
*.LOG_ARCHIVE_FORMAT='%t_%s_%r.arc'
*.LOG_ARCHIVE_MAX_PROCESSES=5
*.FAL_SERVER='dbprimary'
*.FAL_CLIENT='dbstandby'
*.STANDBY_FILE_MANAGEMENT='AUTO'    
    
4.创建group 8 

sql>startup mount;

sql>alter database add standby logfile group 8 ('/data/oracle/oradata/orcl/redo08.log') size 50m;

/data/oracle/oradata/orcl/下多出一个redo08.log文件。
5. 启动到recover mange模式
   sql> shutdown immediate;
   sql>create spfile from pfile;
   sql>startup nomount;
   sql>alter database mount standby database;
   sql>alter database recover managed standby database disconnect from session;  启动到recover mange模式

（五）、启动主库

    oracle>lsnrctl stop 
    oracle>lsnrctl start
    sql>shutdown immediate;    
    sql>startup;  

（六）、验证归档日志是否同步到备库

查看目录/data/oracle/oradata/archive/是否与主库一致。

执行sql>alter system switch logfile;看备库上是否会新增一个归档日志。

此时，备库是无法用plsql连线的，需要将备库切换到read only

（七）、切换备库到read only
 startup mount;
 alter database open read only;
 alter database recover managed standby database using current logfile disconnect from session;

再用plsql就可以连线，只是备库无法修改数据。创建一个表空间，备库中同步新增一个表空间。

（八）、重启测试，主库自动启动，备库需要手动切换到read only

 sqlplus sys as sysdba 
 shutdown immediate;
 startup mount;
 alter database open read only;
 alter database recover managed standby database using current logfile disconnect from session; 
 alter database recover managed standby database cancel;

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

至此，从安装oracle到datagard的配置过程就结束了，希望对你有所帮助。如有问题可以评论探讨，互相学习。