一、 Oracle Data Guard 的简单介绍
DATA GUARD的最主要的功能是冗灾。当然根据配置的不同，DATA GUARD具备以下特点：高可用、性能提升、数据保护以及故障恢复等。
DATA GUARD可以分为物理STANDBY和逻辑STANDBY两种。二者的最大差别在于，物理STANDBY应用的是主库的归档日志，而逻辑STANDBY应用的是主库的归档日志中提取的SQL语句。由于二者这一点的区别，决定了物理STANDBY无论从逻辑结构和物理结构都是和主库保持一致，而逻辑STANDBY则只需保证逻辑结构一致，且逻辑STANDBY在应用SQL语句的时候，数据库可以处于打开的状态。
如果从DATA GUARD的保护模式分，可以分为三种不同的保护模式：
保护最大化：这种模式的配置可以保证主库和备库的同步，任何情况下主库的损毁都不会导致已提交数据的丢失。如果主库和备库之间的网络出现问题，或者备库本身出现问题，都会导致主库停止数据处理。
可用最大化：这种模式和上面一种类似，也是会保证主库和备库的同步，区别在于，当网络或备库不可用时，主库仍然可以继续处理。
性能最大化：主库和备库是异步的。这种模式可能在主库出现损毁时，丢失一部分数据。但是这种模式对主库负荷最小，因此具有最好的性能。
关于DATA GUARD 的介绍请参考Oracle 官方网站，本文主要是介绍如何配置物理 STANDBY。
二、 相关参数说明
主库：
[主机名-dg1.andylhz.com,IP地址-192.168.1.254，实例名-dg，唯一数据库名-dgp，NET服务名-dgp]
备库：
[主机名-dg2.andylhz.com,IP地址-192.168.1.253，实例名-dg，唯一数据库名-dgs，NET服务名-dgs]
三、配置数据库启用归档
因为在安装数据的是一开始就启用了归档，在这里就省略此步骤，不过作为文档就有必要写出操作步骤如下：
SQL>archive log list 看是否启用归档？
如果没有就关闭数据库，并启动到mount的状态，
SQL>startup mount；
SQL>alter database archivelog; 启用归档功能。
SQL>archive log list； 确认结果如图：
四、为主数据库添加’备用联机日志文件’
SQL> alter database add standby logfile group 4
('/u01/app/oracle/oradata/dg/redo04.log') size 50m;
SQL> alter database add standby logfile group 5
('/u01/app/oracle/oradata/dg/redo05.log') size 50m;
SQL> alter database add standby logfile group 6
('/u01/app/oracle/oradata/dg/redo06.log') size 50m;
五、修改主库参数文件
SQL> create pfile from spfile;
文件创建以后可以在$ORACLE_HOME/dbs下找到initdg.ora
vi initdg.ora #标记红色部分为天加的参数
dg.__db_cache_size=83886080
dg.__java_pool_size=4194304
dg.__large_pool_size=4194304
dg.__shared_pool_size=71303168
dg.__streams_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/dg/adump'
*.background_dump_dest='/u01/app/oracle/admin/dg/bdump'
*.compatible='10.2.0.1.0'
*.control_files='/u01/app/oracle/oradata/dg/control01.ctl','/u01/app/oracle/oradata/dg/control02.ctl','/u01/app/oracle/oradata/dg/control03.ctl'
*.core_dump_dest='/u01/app/oracle/admin/dg/cdump'
*.db_block_size=8192
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='dg'
*.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.dispatchers='(PROTOCOL=TCP) (SERVICE=dgXDB)'
*.job_queue_processes=10
*.log_archive_format='%t_%s_%r.dbf'
*.open_cursors=300
*.pga_aggregate_target=16777216
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=167772160
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='/u01/app/oracle/admin/dg/udump'
*.DB_UNIQUE_NAME='dgp'
*.log_archive_config='DG_CONFIG=(dgp,dgs)'
*.log_archive_dest_1='location=/u01/app/oracle/oradata/dg/archive/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=dgp'
*.log_archive_dest_2='SERVICE=dgs arch ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=dgs'
#standby角色转换的参数
*.STANDBY_FILE_MANAGEMENT=AUTO
*.LOG_ARCHIVE_DEST_STATE_1=ENABLE
*.LOG_ARCHIVE_DEST_STATE_2=ENABLE
*.FAL_SERVER='dgs'
*.FAL_CLIENT='dgp'
修改完后保存退出。
关闭主数据库
再用sys 用户连接到数据库，根据修改过的pfile 文件创建 spfile 文件
SQL> shutdown immediate;
Database dismounted.
ORACLE instance shut down.
SQL> create pfile from spfile;
File created.
六、建立备用库的控制文件
SQL> alter database create standby controlfile as '/home/oracle/standby.ctl';
七
[oracle@dg1 ~]$ cat /u01/app/oracle/10g/network/admin/listener.ora
# listener.ora Network Configuration File: /u01/app/oracle/10g/network/admin/listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/10g)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = dg)
(ORACLE_HOME = /u01/app/oracle/10g)
(SID_NAME = dg)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = dg1.andylhz.com)(PORT = 1521))
#(ADDRESS = (PROTOCOL = TCP)(HOST = dg2.andylhz.com)(PORT = 1521))
#在进行switchover 的时候需要将此设置更改
)
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)
[oracle@dg1 ~]$ cat /u01/app/oracle/10g/network/admin/listener.ora
# listener.ora Network Configuration File: /u01/app/oracle/10g/network/admin/listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/10g)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = dg)
(ORACLE_HOME = /u01/app/oracle/10g)
(SID_NAME = dg)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = dg1.andylhz.com)(PORT = 1521))
)
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)
[oracle@dg1 ~]$ cat /u01/app/oracle/10g/network/admin/tnsnames.ora
# tnsnames.ora Network Configuration File: /u01/app/oracle/10g/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
DGP =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = dg1.andylhz.com)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = dg)
)
)
DGS =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = dg2.andylhz.com)(PORT = 1521))
#(ADDRESS = (PROTOCOL = TCP)(HOST = dg1.andylhz.com)(PORT = 1521))
#在进行switchover 的时候需要将此设置更改
)
(CONNECT_DATA =
(SERVICE_NAME = dg)
)
)
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)
八、复制相关文件到备机相应的位置
我在另外的备机上的oracle软件的安装和主库安装位置是一样的。
所以将主库的数据文件和standby控制文件，参数文件initdg.ora 和listener tnsnames 文件，密码文件等复制到备库的相应位置：如下
[oracle@dg1 ~]$ cd /u01/app/oracle/
[oracle@dg1 oracle]$ ll
total 16
drwxr-xr-x 55 oracle oinstall 4096 Jan 23 02:33 10g
drwxr-x--- 3 oracle oinstall 4096 Jan 23 02:05 admin
drwxr-x--- 3 oracle oinstall 4096 Jan 23 02:06 flash_recovery_area
drwxr-x--- 3 oracle oinstall 4096 Jan 23 02:05 oradata
将standby 控制文件 重命名control01.ctl control02.ctl control03.ctl
[oracle@dg2 oradata]$ cd /u01/app/oracle/
[oracle@dg2 oracle]$ ll
total 16
drwxr-xr-x 54 oracle oinstall 4096 Jan 15 16:52 10g
drwxr-x--- 3 oracle oinstall 4096 Jan 23 02:48 admin
drwxr-x--- 4 oracle oinstall 4096 Jan 23 03:17 flash_recovery_area
drwxr-x--- 3 oracle oinstall 4096 Jan 23 02:48 oradata
九、修改备库参数文件和listener、tnsnames文件
[oracle@dg2 oradata]$ vi /u01/app/oracle/10g/dbs/initdg.ora #标记红色部分为天加的参数
dg.__db_cache_size=83886080
dg.__java_pool_size=4194304
dg.__large_pool_size=4194304
dg.__shared_pool_size=71303168
dg.__streams_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/dg/adump'
*.background_dump_dest='/u01/app/oracle/admin/dg/bdump'
*.compatible='10.2.0.1.0'
*.control_files='/u01/app/oracle/oradata/dg/control01.ctl','/u01/app/oracle/oradata/dg/control02.ctl','/u01/app/oracle/oradata/dg/control03.ctl'
*.core_dump_dest='/u01/app/oracle/admin/dg/cdump'
*.db_block_size=8192
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='dg'
*.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.dispatchers='(PROTOCOL=TCP) (SERVICE=dgXDB)'
*.job_queue_processes=10
*.log_archive_format='%t_%s_%r.dbf'
*.open_cursors=300
*.pga_aggregate_target=16777216
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=167772160
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='/u01/app/oracle/admin/dg/udump'
*.DB_UNIQUE_NAME='dgs'
*.log_archive_config='DG_CONFIG=(10gpri,10gstandby)'
*.log_archive_dest_1='location=/u01/app/oracle/oradata/dg/archive/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=10gstandby'
*.log_archive_dest_2='SERVICE=dgp arch ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=dgp'
#standby角色转换的参数
*.STANDBY_FILE_MANAGEMENT=AUTO
*.LOG_ARCHIVE_DEST_STATE_1=ENABLE
*.LOG_ARCHIVE_DEST_STATE_2=ENABLE
*.FAL_SERVER='dgp'
*.FAL_CLIENT='dgs'
然后保存退出：
用sys用户登录备库后创建spfile
SQL> create pfile from spfile;
File created.
注：备库的listener 和tnsnames 文件中的参数是一样的，只是主机名/IP需要做修改即可。
十、测试主库备库的连通性
启动主库监听：lsnrctl start
[oracle@dg2 oradata]$ tnsping dgp
TNS Ping Utility for Linux: Version 10.2.0.1.0 - Production on 23-JAN-2012 05:18:45
Copyright (c) 1997, 2005, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = dg1.andylhz.com)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = dg)))
OK (10 msec)
启动备库监听: lsnrctl start
[oracle@dg1 dg]$ tnsping dgs
TNS Ping Utility for Linux: Version 10.2.0.1.0 - Production on 23-JAN-2012 05:29:10
Copyright (c) 1997, 2005, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = dg2.andylhz.com)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = dg)))
OK (20 msec)
十一、打开备库主库
SQL> startup mount;#备库以mount方式打开
启动redolog应用：
SQL> alter database recover managed standby database disconnect from session;
SQL> startup； #主库正常打开
切换日志文件：
SQL> alter system switch logfile;
主库日志显示
备库日志
备库成功应用了主库的归档日志
本文转自andylhz 51CTO博客，原文链接：http://blog.51cto.com/andylhz2009/772921，如需转载请自行联系原作者
