之前整理的RMAN有关还原的文章:
RMAN系列(五)---- RMAN还原与恢复
http://blog.youkuaiyun.com/xujinyang/article/details/6838045
RMAN备份与恢复实例
http://blog.youkuaiyun.com/xujinyang/article/details/6822620
Oracle Rman跨resetlogs版本恢复
http://blog.youkuaiyun.com/xujinyang/article/details/6830337
RAC下的RMAN讲究的是备份和还原的策略要一致。备份策略的不同,会导致备份结果的分步不同,进而影响恢复的策略和步骤。一般情况下,恢复策略和备份策略必须是对应的。如果备份策略进行了修改,那么恢复也应该采用相同的策略。之前我们的RMAN备份参考:
RAC之RMAN备份
http://blog.youkuaiyun.com/xujinyang/article/details/6837226
这里面有2个注意事项:
1.执行恢复的节点要能看到所有节点的归档文件。这个在RAC备份那篇里已经讲了方法,就是把归档文件传送到其他节点,这样就能够看到所有节点的归档文件了。
2.备份集的存放问题。如果我们放在共享设备上,那么节点可以访问所有的备份文件,那么就可以直接进行恢复操作。如果不是放在共享设备,可以通过NFS mount来挂载,或者设置2个通道。分别指向多个实例。
示例:
1.1先停止数据库
[oracle@rac1 bin]$srvctl stop db -d orcl
[oracle@rac1 bin]$crs_stat -t
NameTypeTargetStateHost
------------------------------------------------------------
ora.orcl.dbapplicationOFFLINEOFFLINE
ora....oltp.cs applicationOFFLINEOFFLINE
ora....cl1.srv applicationOFFLINEOFFLINE
ora....cl2.srv applicationOFFLINEOFFLINE
ora....l1.inst applicationOFFLINEOFFLINE
ora....l2.inst applicationOFFLINEOFFLINE
ora....SM1.asm applicationONLINEONLINErac1
ora....C1.lsnr applicationONLINEONLINErac1
ora.rac1.gsdapplicationONLINEONLINErac1
ora.rac1.onsapplicationONLINEONLINErac1
ora.rac1.vipapplicationONLINEONLINErac1
ora....SM2.asm applicationONLINEONLINErac2
ora....C2.lsnr applicationONLINEONLINErac2
ora.rac2.gsdapplicationONLINEONLINErac2
ora.rac2.onsapplicationONLINEONLINErac2
ora.rac2.vipapplicationONLINEONLINErac2
1.2将节点启动到mount状态:
备份集存在在2个节点的情况(2个节点的RAC),在这种情况下,需要分配2个通道分别连接对应的节点。每个节点都需要启动到mount状态。因为每个节点都有备份文件,所以在每个节点都需要执行restore,如果没有启动的话,就会报错,对于备份集存放在共享设备的就不用这么麻烦。
[oracle@rac1 bin]$export ORACLE_SID=orcl1
[oracle@rac1 bin]$rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Mon Sep 27 02:56:55 2010
Copyright (c) 1982, 2005, Oracle.All rights reserved.
connected to target database (not started)
RMAN>startup mount;
Oracle instance started
database mounted
Total System Global Area180355072 bytes
Fixed Size1218388 bytes
Variable Size100665516 bytes
Database Buffers75497472 bytes
Redo Buffers2973696 bytes
[oracle@rac2 bin]$ export ORACLE_SID=orcl2
[oracle@rac2 bin]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Mon Sep 27 02:57:44 2010
Copyright (c) 1982, 2005, Oracle.All rights reserved.
connected to target database (not started)
RMAN> startup mount;
Oracle instance started
database mounted
Total System Global Area180355072 bytes
Fixed Size1218388 bytes
Variable Size83888300 bytes
Database Buffers92274688 bytes
Redo Buffers2973696 bytes
1.3完全恢复
在任意一个节点上执行:
RMAN>RUN {
allocate channel c1 device type disk connect'sys/oracle@orcl1';
allocate channel c2 device type disk connect'sys/oracle@orcl2';
restore database;
recover database;
}
2> 3> 4> 5> 6>
using target database control file instead of recovery catalog
allocated channel: c1
channel c1: sid=146 instance=orcl1 devtype=DISK
allocated channel: c2
channel c2: sid=146 instance=orcl2 devtype=DISK
Starting restore at 27-SEP-10
skipping datafile 2; already restored to file +DATA/orcl/datafile/undotbs1.278.730181053
skipping datafile 3; already restored to file +DATA/orcl/datafile/sysaux.277.730181053
skipping datafile 5; already restored to file +DATA/orcl/datafile/undotbs2.284.730181347
skipping datafile 1; already restored to file +DATA/orcl/datafile/system.276.730181051
skipping datafile 4; already restored to file +DATA/orcl/datafile/users.279.730181053
skipping datafile 7; already restored to file +DATA/orcl/datafile/anhuianqing.dbf
Finished restore at 27-SEP-10
Starting recover at 27-SEP-10
starting media recovery
media recovery complete, elapsed time: 00:00:04
Finished recover at 27-SEP-10
released channel: c1
released channel: c2
RMAN> sql 'alter database open';
sql statement: alter database open
1.4不完全恢复
1.4.1基于时间点的恢复
RMAN>RUN {
allocate channel c1 device type disk connect'sys/oracle@orcl1';
allocate channel c2 device type disk connect'sys/oracle@orcl2';
set until time "to_date('2010/9/27 03:30:00','yyyy/mm/dd hh24:mi:ss')";
restore database;
recover database;
}
2>3> 4> 5> 6> 7> 8>
allocated channel: c1
channel c1: sid=143 instance=orcl1 devtype=DISK
allocated channel: c2
channel c2: sid=146 instance=orcl2 devtype=DISK
executing command: SET until clause
Starting restore at 27-SEP-10
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to +DATA/orcl/datafile/system.276.730181051
restoring datafile 00004 to +DATA/orcl/datafile/users.279.730181053
restoring datafile 00007 to +DATA/orcl/datafile/anhuianqing.dbf
channel c1: reading from backup piece /u01/backup/orcl_2blotmnp_1_1_20100927
channel c2: starting datafile backupset restore--这里使用了2个通道,因为这个测试的备份集是放在2个节点的。
channel c2: specifying datafile(s) to restore from backup set
restoring datafile 00002 to +DATA/orcl/datafile/undotbs1.278.730181053
restoring datafile 00003 to +DATA/orcl/datafile/sysaux.277.730181053
restoring datafile 00005 to +DATA/orcl/datafile/undotbs2.284.730181347
channel c2: reading from backup piece /u01/backup/orcl_2clotmno_1_1_20100927
channel c2: restored backup piece 1
piece handle=/u01/backup/orcl_2clotmno_1_1_20100927 tag=ORCL_HOT_DB_BK
channel c2: restore complete, elapsed time: 00:01:21
channel c1: restored backup piece 1
piece handle=/u01/backup/orcl_2blotmnp_1_1_20100927 tag=ORCL_HOT_DB_BK
channel c1: restore complete, elapsed time: 00:02:48
Finished restore at 27-SEP-10
Starting recover at 27-SEP-10
starting media recovery
media recovery complete, elapsed time: 00:00:03
Finished recover at 27-SEP-10
released channel: c1
released channel: c2
RMAN>
恢复完成之后,在两个节点执行:
alter database open resetlogs;
打开数据即可。
1.4.2基于SCN的恢复
当前SCN查看方法:
SQL> select current_scn from v$database;
CURRENT_SCN
-----------
1118216
RMAN>RUN {
allocate channel c1 device type disk connect'sys/oracle@orcl1';
allocate channel c2 device type disk connect'sys/oracle@orcl2';
restore database until scn 1118215 ;
recover database until scn 1118215 ;
}
2> 3> 4> 5> 6>
using target database control file instead of recovery catalog--非catalog模式,这种模式备份控制文件非常重要
allocated channel: c1
channel c1: sid=142 instance=orcl1 devtype=DISK
allocated channel: c2
channel c2: sid=151 instance=orcl2 devtype=DISK
Starting restore at 27-SEP-10
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to +DATA/orcl/datafile/system.276.730181051
restoring datafile 00004 to +DATA/orcl/datafile/users.279.730181053
restoring datafile 00007 to +DATA/orcl/datafile/anhuianqing.dbf
channel c1: reading from backup piece /u01/backup/orcl_2blotmnp_1_1_20100927
channel c2: starting datafile backupset restore
channel c2: specifying datafile(s) to restore from backup set
restoring datafile 00002 to +DATA/orcl/datafile/undotbs1.278.730181053
restoring datafile 00003 to +DATA/orcl/datafile/sysaux.277.730181053
restoring datafile 00005 to +DATA/orcl/datafile/undotbs2.284.730181347
channel c2: reading from backup piece /u01/backup/orcl_2clotmno_1_1_20100927
channel c2: restored backup piece 1
piece handle=/u01/backup/orcl_2clotmno_1_1_20100927 tag=ORCL_HOT_DB_BK
channel c2: restore complete, elapsed time: 00:03:58
channel c1: restored backup piece 1
piece handle=/u01/backup/orcl_2blotmnp_1_1_20100927 tag=ORCL_HOT_DB_BK
channel c1: restore complete, elapsed time: 00:05:47
Finished restore at 27-SEP-10
Starting recover at 27-SEP-10
starting media recovery
archive log thread 1 sequence 44 is already on disk as file /u02/rac1_arch/1_44_730181171.dbf
archive log thread 2 sequence 38 is already on disk as file /u02/rac1_arch/2_38_730181171.dbf
archive log thread 1 sequence 1 is already on disk as file /u02/rac1_arch/1_1_730784806.dbf
archive log thread 2 sequence 1 is already on disk as file /u02/rac2_arch/2_1_730784806.dbf
archive log filename=/u02/rac1_arch/1_44_730181171.dbf thread=1 sequence=44
archive log filename=/u02/rac1_arch/2_38_730181171.dbf thread=2 sequence=38
archive log filename=/u02/rac2_arch/2_1_730784806.dbf thread=2 sequence=1
media recovery complete, elapsed time: 00:00:09
Finished recover at 27-SEP-10
released channel: c1
released channel: c2
恢复结束,用alter database open resetlogs打开数据库。
小结:
以上都是简单的测试,具体情况还是要具体对待。经验积累的多了,就知道怎么处理了。总之,备份重于一切。有了备份,才有恢复的可能。
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