RAC数据恢复至单机环境
一、概括
随着越来越多的RAC环境，将RAC数据迁移至单机环境下的需求也随之增加，怎样才能更有效的迁移呢，方法有许多逻辑迁移（exp/expdp）、RMAN、DG、goldengate等，我们可根据自身环境及需求选择相应的迁移方式，下面简单介绍一下使用RMAN将RAC数据迁移至单机环境中的步骤。
二、 模拟环境：整套RAC环境无故宕机，暂无法恢复，我们将之前备份的数据进行恢复
将最近一次全备份文件上传至目标环境，并查看文件信息
[Oracle@oradb1 backup]$ pwd
/oracle/backup
[oracle@oradb1 backup]$ ls -lrt
总计 264312
-rw-r----- 1 oracle oinstall 132608 02-17 13:24 arch_0lp0ro84
-rw-r----- 1 oracle oinstall 19456 02-17 13:24 arch_0ip0ro4u
-rw-r----- 1 oracle oinstall 1114112 02-17 13:24 full_0kp0ro7v_1_1
-rw-r----- 1 oracle oinstall 269107200 02-17 13:24 full_0jp0ro50_1_
通过上述我们可以看到，归档文件有两个，由于是测试环境，数据量及备份信息较简单，数据文件也是两个，由此得知文件full_0kp0ro7v_1_1存放参数文件和控制文件。
设置环境变量
[oracle@oradb1 ~]$ vi ~/.bash_profile
修改参数为：export ORACLE_SID=racdb1
恢复spfile文件
[oracle@oradb1 backup]$ rman target /
Recovery Manager: Release 11.2.0.4.0 - Production on Mon Feb 17 11:37:45 2014
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
connected to target database (not started)
RMAN> startup force nomount;
startup failed: ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file '/oracle/db_1/dbs/initracdb1.ora'
starting Oracle instance without parameter file for retrieval of spfile
Oracle instance started
Total System Global Area 1068937216 bytes
Fixed Size 2260088 bytes
Variable Size 281019272 bytes
Database Buffers 780140544 bytes
Redo Buffers 5517312 bytes
RMAN> restore spfile from '/oracle/backup/full_0kp0ro7v_1_1';
Starting restore at 17-FEB-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
channel ORA_DISK_1: restoring spfile from AUTOBACKUP /oracle/backup/full_0kp0ro7v_1_1
channel ORA_DISK_1: SPFILE restore from AUTOBACKUP complete
Finished restore at 17-FEB-14
RMAN> restore spfile from '/oracle/backup/full_0kp0ro7v_1_1';
Starting restore at 17-FEB-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
channel ORA_DISK_1: restoring spfile from AUTOBACKUP /oracle/backup/full_0kp0ro7v_1_1
channel ORA_DISK_1: SPFILE restore from AUTOBACKUP complete
Finished restore at 17-FEB-14
登录到数据库，生成pfile文件，并编辑，删除与集群即节点2相关参数，修改控制文件及其他目录路径，并根据需求创建相应目录（如闪回区、oracle基础目录）
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在CentOS 6.4下安装Oracle 11gR2(x64)
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idle> create pfile from spfile;
File created.
创建spfile，并重启实例
idle> create spfile from pfile;
File created.
idle> show parameter pfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string
idle> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string
idle> shutdown abort
ORACLE instance shut down.
idle> startup nomount
ORACLE instance started.
Total System Global Area 534462464 bytes
Fixed Size 2254952 bytes
Variable Size 213911448 bytes
Database Buffers 314572800 bytes
Redo Buffers 3723264 bytes
idle> show parameter pfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string /oracle/db_1/dbs/spfileracdb1.
Ora
恢复控制文件，并启动数据库到mount模式
[oracle@oradb1 oracle]$ rman target /
Recovery Manager: Release 11.2.0.4.0 - Production on Mon Feb 17 12:45:58 2014
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
connected to target database: RACDB (not mounted)
RMAN> restore controlfile from '/oracle/backup/full_0bp0rlcu_1_1';
Starting restore at 17-FEB-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:15
output file name=/oracle/oradata/racdb/current.273.839446247
output file name=/oracle/oradata/racdb/current.274.839446249
Finished restore at 17-FEB-14
RMAN> sql 'alter database mount';
sql statement: alter database mount
released channel: ORA_DISK_1