探索ORACLE之RMAN_07单个数据文件丢失恢复

探索ORACLE之RMAN_07单个数据文件丢失恢复

作者：吴伟龙   Name：Prodence Woo

QQ：286507175  msn:[email protected]

 

备份的终极目的是为了更好的将数据恢复和还原过来，在前面的章节中我们已经重点谈完了RMAN的备份，实际上也穿插的谈了些复杂的完整恢复。当然在这节当中我们将会由浅入深的详细谈谈在几种不同情况下的数据库恢复。

1、     数据文件的丢失恢复

1.1    在wwl表空间上创建5张表，并添加数据。

SQL> create table wwl01 (id number(3),namevarchar2(10));

Table created.

 

SQL> insert into wwl01 values(1,'wwl');

1 row created.

 

SQL> insert into wwl01 values(2,'wm');

1 row created.

 

SQL> insert into wwl01 values(3,'zq');

1 row created.

 

SQL> insert into wwl01 values(4,'wbq');

1 row created.

 

SQL> insert into wwl01 values(5,'wq');

1 row created.

 

SQL> create table wwl02 as select * from wwl01;

Table created.

 

SQL> create table wwl03 as select * from wwl01;

Table created.

 

SQL> create table wwl04 as select * from wwl01;

Table created.

 

SQL> create table wwl05 as select * from wwl01;

Table created.

 

查看表中的数据：

SQL> select * from tab;

 

TNAME     TABTYPE  CLUSTERID

---------- ------- ----------

WWL01      TABLE

WWL02      TABLE

WWL03      TABLE

WWL04      TABLE

WWL05      TABLE

1.2    执行全库备份

[oracle@wwldb ~]$ rman target /

Recovery Manager: Release 10.2.0.1.0 - Production on Fri Jun 2200:59:59 2012

Copyright (c) 1982, 2005, Oracle. All rights reserved.

 

connected to target database: WWL (DBID=5520179)

 

RMAN> backup database;

 

1.3    模拟数据丢失，手动删除数据文件wwl001.dbf

[oracle@wwldb WWL]$ rm -rfwwl001.dbf

 

1.4    再次启动数据库，无法启动并报错不能锁定数据文件5，查看dbwr的跟踪文件。

SQL>startup force;

ORACLEinstance started.

 

TotalSystem Global Area  285212672 bytes

FixedSize                  1218968 bytes

VariableSize              92276328 bytes

DatabaseBuffers          184549376 bytes

RedoBuffers                7168000 bytes

Databasemounted.

ORA-01157:cannot identify/lock data file 5 - see DBWR trace file

ORA-01110: data file 5:'/DBData/WWL/wwl001.dbf'

 

1.5    检查跟踪文件，报如下错误，非常的清楚的告诉了找不到的文件：

Errors in file /DBSoft/admin/WWL/bdump/wwl_dbw0_29185.trc:

ORA-01157: Message 1157 not found; No messagefile for product=RDBMS, facility=ORA; arguments: [5]

ORA-01110: Message 1110 not found; No messagefile for product=RDBMS, facility=ORA; arguments: [5] [/DBData/WWL/wwl001.dbf]

ORA-27037: Message 27037 not found; No messagefile for product=RDBMS, facility=ORA

Linux Error: 2: No such file or directory

Additional information: 3

ORA-1157 signalled during: ALTER DATABASEOPEN...

由以上信息可以得出数据库故障是由于数据文件wwl001.dbf数据文件异常丢失或者损坏导致数据库的故障，那么数据文件丢失就必然存在数据库数据的丢失，但是万幸的是，在丢失之前我们已经做过备份了，现在我们就来通过之前的备份将wwl001.dbf文件恢复回来，数据文件的恢复分为两种，一直是在不影响数据库其它业务情况下的在线联机恢复，还有一种是停机停业务的恢复，详细见如下：

 

1.6    恢复方法一，零停机，在线恢复

开始执行恢复操作，分为如下七个步骤：

1、强制将数据库启动到mount状态

RMAN>startup force mount;

Oracle instancestarted

databasemounted

Total System GlobalArea     285212672 bytes

Fixed Size                     1218968 bytes

VariableSize                 92276328 bytes

DatabaseBuffers             184549376 bytes

RedoBuffers                   7168000 bytes

 

2、将对应的数据文件offline

SQL> alter database datafile '/DBData/WWL/wwl001.dbf' offline;

Database altered.

 

3、开启数据库

SQL> alter database open;

Database altered.

 

4、将数据文件从备份中restore出来

RMAN> restore datafile'/DBData/WWL/wwl001.dbf';

Starting restore at 22-JUN-12

using target database control fileinstead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=141devtype=DISK

channel ORA_DISK_1: startingdatafile backupset restore

channel ORA_DISK_1: specifyingdatafile(s) to restore from backup set

restoring datafile 00005 to /DBData/WWL/wwl001.dbf

channel ORA_DISK_1: reading frombackup piece /DBBak/bak_WWL_06_22_0vne4ph6_1_1

channel ORA_DISK_1: restored backuppiece 1

piecehandle=/DBBak/bak_WWL_06_22_0vne4ph6_1_1 tag=TAG20120622T010021

channel ORA_DISK_1: restorecomplete, elapsed time: 00:00:07

Finished restore at 22-JUN-12

 

查看到数据文件已经restore出来了。

[oracle@wwldb WWL]$ ll wwl*

-rw-r----- 1 oracle oinstall52436992 Jun 22 01:21 wwl001.dbf

-rw-r----- 1 oracle oinstall  5251072 Jun 22 01:20 wwl002.dbf

-rw-r----- 1 oracle oinstall  5251072 Jun 22 01:20 wwl003.dbf

 

5、执行数据恢复，保证scn一致

RMAN>recover datafile '/DBData/WWL/wwl001.dbf';

Startingrecover at 22-JUN-12

using targetdatabase control file instead of recovery catalog

allocatedchannel: ORA_DISK_1

channelORA_DISK_1: sid=144 devtype=DISK

starting mediarecovery

media recoverycomplete, elapsed time: 00:00:01

Finishedrecover at 22-JUN-12

 

RMAN>

 

6、将数据文件在线

SQL> conn / as sysdba

Connected.

SQL> alter database datafile'/DBData/WWL/wwl001.dbf' online;

 

Database altered.

 

7、验证数据是否恢复，可以看到数据全部恢复回来了。

SQL>conn wwl/wwl

Connected.

SQL>select * from tab;

 

TNAME                          TABTYPE  CLUSTERID

------------------------------------- ----------

WWL01                          TABLE

WWL02                          TABLE

WWL03                          TABLE

WWL04                          TABLE

WWL05                          TABLE

 

SQL>select count(*) from tab;

 

  COUNT(*)

----------

         5

 

SQL>

 

1.7    恢复方法二，离线恢复

开始执行恢复操作，分为五个步骤：

1、强制将数据库启动到mount状态

SQL> startupforce mount;

ORACLE instancestarted.

Total SystemGlobal Area  285212672 bytes

Fixed Size                  1218968 bytes

VariableSize              96470632 bytes

DatabaseBuffers          180355072 bytes

RedoBuffers                7168000 bytes

Databasemounted.

 

2、将数据文件从备份中restore出来

RMAN> restoredatafile '/DBData/WWL/wwl002.dbf'

2> ;

Starting restoreat 22-JUN-12

using targetdatabase control file instead of recovery catalog

allocatedchannel: ORA_DISK_1

channelORA_DISK_1: sid=156 devtype=DISK

 

channelORA_DISK_1: starting datafile backupset restore

channelORA_DISK_1: specifying datafile(s) to restore from backup set

restoringdatafile 00006 to /DBData/WWL/wwl002.dbf

channelORA_DISK_1: reading from backup piece /DBBak/bak_WWL_06_22_0vne4ph6_1_1

channelORA_DISK_1: restored backup piece 1

piecehandle=/DBBak/bak_WWL_06_22_0vne4ph6_1_1 tag=TAG20120622T010021

channelORA_DISK_1: restore complete, elapsed time: 00:00:01

Finished restoreat 22-JUN-12

 

3、执行数据恢复，保证scn一致

RMAN> recover datafile '/DBData/WWL/wwl002.dbf';

Starting recover at 22-JUN-12

using channel ORA_DISK_1

starting media recovery

media recovery complete, elapsed time: 00:00:02

Finished recover at 22-JUN-12

RMAN>

 

4、开启数据库

SQL> conn /as sysdba

Connected.

SQL> alterdatabase open;

Databasealtered.

 

5、验证数据是否恢复

SQL> select *from tab;

TNAME                          TABTYPE  CLUSTERID

------------------------------------- ----------

WWL01                          TABLE

WWL02                          TABLE

WWL03                          TABLE

WWL04                          TABLE

WWL05                          TABLE

 

SQL> selectcount(*) from wwl01;

  COUNT(*)

----------

         5

SQL>