Oracle DataGuard是一种数据库级别的HA方案，最主要功能是冗灾、数据保护、故障恢复等。
在生产数据库的"事务一致性"时，使用生产库的物理全备份(或物理COPY)创建备库，备库会通过生产库传输过来的归档日志(或重做条目)自动维护备用数据库。将重做数据应用到备用库。本文介绍使用RMAN备份创建备库(dataguard).
一:Oracle DataGuard环境概述
1.软件环境
操作系统Red Linux Enterprise as 5
数据库版本Oracle 10g release 2
2.primary databae
IP:192.168.18.1
ORACLE_SID=db1
db_unique_name=db1
3.standby database
IP:192.168.18.2
ORACLE_SID=standby
db_unique_name=standby
二,主数据库(db1)做准备
1.设置主数据库为Force logging
SQL> alter database force logging; 2.创建密码文件
cd $ORACLE_HOME/dbs/ orapwdfile=orapwdb1 password=123456 force=y 3.修改主库的初始化参数
alter system set log_archive_config='dg_config=(db1,standby)' scope=both; alter system set log_archive_dest_1='location=/u01/db1/arch' scope=both; alter system set db_unique_name='db1' scope=both; 4.生成数据库备份
RMAN> connect target sys/123456 RMAN> backup database format='/oracle/rmanback/%d_%s.dbf' plus archivelog; [oracle@oracle rmanback]$ ls DB1_1.dbfDB1_2.dbf 5.生成备库的control file
SQL>alter database create standby controlfile as '/oracle/rmanback/ctontrl01.ctl 6.配置listener.ora 和tnsnames.ora文件
启动lintener.ora,
[oracle@oracle dbs]$ lsnrctl status LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 14-JUN-2009 02:54:29 Service "db1" has 1 instance(s). Instance "db1", status READY, has 1 handler(s) for this service... Service "db1_XPT" has 1 instance(s). Instance "db1", status READY, has 1 handler(s) for this service... The command completed successfully 配置rnsnames.ora
vi $ORACLE_HOME/network/admin/tnsnames.ora db1 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.18.1)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = db1) standby = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.18.2)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = standby) ) ) 三.创建standby database
1.设置环境变量并安装oracle软件
#环境变量设成与主库一样 #只安装软件不安装库 ./runInstaller –silent –responseFile /tmp/installoracle.rsp 2.建立相关的目录
cd $ORACLE_HOME/dbs/ orapwdfile=orapwSID password=123456 force=y #注要密码要与主库的一样, 否则会归档失败 3.建立密码文件
cd $ORACLE_HOME/dbs/ orapwd file=orapwSID password=123456 force=y #注要密码要与主库的一样, 否则会归档失败 3.建立参数文件(pfile)
db_name = standby shared_pool_size = 120M undo_management = AUTO undo_tablespace = undotbs sga_max_size = 200M sga_target = 160M db_2k_cache_size = 4M standby_file_management=AUTO fal_server='db1' fal_client='standby' log_archive_dest_1='location=/u01/app/oracle/product/10.2.0/dbs/arch' log_archive_dest_2='SERVICE=db1 REOPEN=300' log_archive_dest_state_1='ENABLE' log_archive_dest_state_2='ENABLE' 4.CP主数据库RMAN备份及控制文件到备库
注意:备份存放位置要与primary database RMAN备份文件的位置相同. 控制文件存放位置要与生成standby database controlfile的位置相同
scp /oracle/rmanback/*.dbf root@192.168.18.2:/oracle/rmanback/ scp /oracle/rmanback/*.ctl root@192.168.18.2:/oracle/oracle/oradata/standby/ 5.利用备用的控制文件,把备用数据库启到mount
SQL>connect / as sysdba connnpcted to an idle instance． SQL>startup nomount pfile=$ORACLE_HOME/dbs/initstandby.ora SQL>alter database mount standby database 6. 配置listener.ora 和tnsnames.ora文件.
与主库相同启动listener,tnsnames.ora也与主库配置的一样,
当主备库的监听都启动后,进行测试,以例下面能顺利进行
tnsping db1 tnsping standby SQL> sqlplus sys/123456@db1 SQL> sqlplus sys/123456@standby 7.转储数据库
RMAN>connect target / connected to target database：TEST(DBID=788075692) RMAN> restore database 8.恢复数据库。
SQL>recover managed standby database disconnect from session； #如果有需要应用的日志并想手工应用，可以运行如下命令 SQL>recover automatic standby database； 9.检查standby database是否创建成功
a.在primary database 上切换日志
SQL> alter system switch logfile b.在primary database上运行下面的语句
SQL> select max(sequence#) from v$archived_log; MAX(SEQUENCE#) -------------- 17 c. 在standby database上运行下面的语句
SQL> select sequence# ,applied from v$archived_log order by sequence#; SEQUENCE# APP --------------------- --- 15YES 16YES 17YES 若在上步中的max sequence#在的的app状态为YES说明standby database 成功创建.
10. 以spfile启动并设为只读
SQL> create spfile from pfile; SQL> shutdown immedaite SQL> startup mount SQL> alter database recover managed standby database disconnect from session; SQL> alter database open read only; 以上就是Oracle DataGuard数据备份的操作流程。本文出自 “追求” 博客