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2008-07-16 17:17:04

Normal 0 7.8 磅 0 2 false false false MicrosoftInternetExplorer4 第四章. 数据库恢复案例

4.1非归档模式下的备份与恢复

备份方案:采用OS冷备份

1.连接数据库并创建测试表

SQL*Plus: Release 8.1.6.0.0 - Production on Tue May 6 13:46:32 2003

(c) Copyright 1999 Oracle Corporation.  All rights reserved.

SQL> connect internal/password as sysdba;

Connected.

SQL> create table test(a int);

Table created

SQL> insert into test values(1);

1 row inserted

SQL> commit;

Commit complete

 

2.备份数据库

SQL> @coldbak.sql 或在DOS svrmgrl @coldbak.sql

 

3.再插入记录

SQL> insert into test values(2);

1 row inserted

SQL> commit;

Commit complete

SQL> select * from test;

                         A

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

                         1

                         2

4.关闭数据库

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

 

5.毁坏一个或多个数据文件,如删除user01.dbf

C:\>del D:\ORACLE\ORADATA\TEST\USERS01.DBF

模拟媒体毁坏

 

6.重新启动数据库,会发现如下错误

SQL> startup

ORACLE instance started.

 

Total System Global Area  102020364 bytes

Fixed Size                    70924 bytes

Variable Size              85487616 bytes

Database Buffers           16384000 bytes

Redo Buffers                  77824 bytes

Database mounted.

ORA-01157: cannot identify/lock data file 3 - see DBWR trace file

ORA-01110: data file 3: 'D:\ORACLE\ORADATA\TEST\USERS01.DBF'

 

在报警文件中,会有更详细的信息

Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:

ORA-01157: cannot identify/lock data file 3 - see DBWR trace file

ORA-01110: data file 3: 'D:\ORACLE\ORADATA\TEST\USERS01.DBF'

ORA-27041: unable to open file

OSD-04002: unable to open file

O/S-Error: (OS 2) 系统找不到指定的文件。

 

7.拷贝备份复原到原来位置(restore过程)

C:\>xcopy d:\database\*.* d:\oracle\oradata\test/H/R/S

 

8.打开数据库,检查数据

SQL> alter database open;

Database altered.

SQL> select * from test;

                         A

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

                         1

 

这里可以发现,数据库恢复成功,但在备份之后与崩溃之前的数据丢失了。

说明:

1、非归档模式下的恢复方案可选性很小,一般情况下只能有一种恢复方式,就是数据库的冷备份的完全恢复,仅仅需要拷贝原来的备份就可以(restore),不需要recover

2、这种情况下的恢复,可以完全恢复到备份的点上,但是可能是丢失数据的,在备份之后与崩溃之前的数据将全部丢失。

3、不管毁坏了多少数据文件或是联机日志或是控制文件,都可以通过这个办法恢复,因为这个恢复过程是Restore所有的冷备份文件,而这个备份点上的所有文件是一致的,与最新的数据库没有关系,就好比把数据库又放到了一个以前的“点”上。

4、对于非归档模式下,最好的办法就是采用OS的冷备份,建议不要用RMAN来作冷备份,效果不好,因为RMAN不备份联机日志,restore不能根本解决问题。

5、如果没有备份联机日志,如RMAN的备份,就需要利用不完全恢复(until cancel)的方法来重新创建联机日志文件

4.2归档模式下丢失或损坏一个数据文件

4.2.1 OS备份方案

在归档方式下损坏或丢失一个数据文件,如果存在相应的备份与该备份以来的归档日志,恢复还是比较简单的,可以作到尽量少的Down机时间,并能作到数据库的完全恢复。

1、连接数据库,创建测试表并插入记录

SQL*Plus: Release 8.1.6.0.0 - Production on Tue May 6 13:46:32 2003

(c) Copyright 1999 Oracle Corporation.  All rights reserved.

SQL> connect internal/password as sysdba;

Connected.

SQL> create table test(a int) tablespace users;

Table created

SQL> insert into test values(1);

1 row inserted

SQL> commit;

Commit complete

 

2、备份数据库

SQL> @hotbak.sql 或在DOS svrmgrl @hotbak.sql

 

3、继续在测试表中插入记录

SQL> insert into test values(2);

1 row inserted

SQL> commit;

Commit complete

SQL> select * from test;

                         A

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

                         1

                         2

SQL> alter system switch logfile;

System altered.

SQL> alter system switch logfile;

System altered.

 

4、关闭数据库,模拟丢失数据文件

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down

C:\>del D:\ORACLE\ORADATA\TEST\USERS01.DBF

模拟媒体毁坏

 

5、启动数据库错误,脱机该数据文件

SQL> startup

ORACLE instance started.

 

Total System Global Area  102020364 bytes

Fixed Size                    70924 bytes

Variable Size              85487616 bytes

Database Buffers           16384000 bytes

Redo Buffers                  77824 bytes

Database mounted.

ORA-01157: cannot identify/lock data file 3 - see DBWR trace file

ORA-01110: data file 3: 'D:\ORACLE\ORADATA\TEST\USERS01.DBF'

还可以查看报警文件(见上一个恢复案例)或动态视图v$recover_file

SQL> select * from v$recover_file;

 

     FILE# ONLINE  ERROR                 CHANGE# TIME

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

         3 ONLINE                        1013500 2003-05-07

 

脱机数据文件

SQL> alter database datafile 3 offline drop;

Database altered.

 

6、打开数据库,拷贝备份回来(restore),恢复(recover)该数据文件,并联机

SQL> alter database open;

Database altered.

拷贝备份从备份处

copy d:\databak\ users01.dbf d:\oracle\oradata\test;

恢复该数据文件

SQL> recover datafile 3;

ORA-00279: change 1053698 generated at 05/07/2003 17:51:26 needed for thread 1

ORA-00289: suggestion : D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00304.ARC

ORA-00280: change 1053698 for thread 1 is in sequence #304

 

Specify log: {=suggested | filename | AUTO | CANCEL}

AUTO

ORA-00279: change 1053701 generated at 05/07/2003 17:51:39 needed for thread 1

ORA-00289: suggestion : D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00305.ARC

ORA-00280: change 1053701 for thread 1 is in sequence #305

ORA-00278: log file 'D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00304.ARC' no

longer needed for this recovery

 

Log applied.

Media recovery complete.

恢复成功,联机该数据文件

SQL> alter database datafile 3 online;

Database altered.

 

7、检查数据库的数据(完全恢复)

SQL> select * from test;

                         A

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

                         1

                         2

说明:

1、采用热备份,需要运行在归档模式下,可以实现数据库的完全恢复,也就是说,从备份后到数据库崩溃时的数据都不会丢失。

2、可以采用全备份数据库的方式备份,对于特殊情况,也可以只备份特定的数据文件,如只备份用户表空间(一般情况下对于某些写特别频繁的数据文件,可以单独加大备份频率)

3、如果在恢复过程中,发现损坏的是多个数据文件,即可以采用一个一个数据文件的恢复方法(第5步中需要对数据文件一一脱机,第6步中需要对数据文件分别恢复),也可以采用整个数据库的恢复方法。

4、如果是系统表空间的损坏,不能采用此方法

4.2.2 RMAN备份方案

RMAN也可以进行联机备份,而且备份与恢复方法将比OS备份更简单可靠。

1、连接数据库,创建测试表并插入记录

SQL*Plus: Release 8.1.6.0.0 - Production on Tue May 6 13:46:32 2003

(c) Copyright 1999 Oracle Corporation.  All rights reserved.

SQL> connect internal/password as sysdba;

Connected.

 

SQL> create table test(a int) tablespace users;

Table created

SQL> insert into test values(1);

1 row inserted

SQL> commit;

Commit complete

 

2、备份数据库表空间users

C:\>rman

Recovery Manager: Release 8.1.6.0.0 - Production

RMAN> connect rcvcat rman/rman@back

RMAN-06008: connected to recovery catalog database

RMAN> connect target internal/virpure

RMAN-06005: connected to target database: TEST (DBID=1788174720)

 

RMAN> run{

2> allocate channel c1 type disk;

3> backup tag 'tsuser' format 'd:\backup\tsuser_%u_%s_%p'

4> tablespace users;

5> release channel c1;

6> }

 

RMAN-03022: compiling command: allocate

RMAN-03023: executing command: allocate

RMAN-08030: allocated channel: c1

RMAN-08500: channel c1: sid=16 devtype=DISK

 

RMAN-03022: compiling command: backup

RMAN-03025: performing implicit partial resync of recovery catalog

RMAN-03023: executing command: partial resync

RMAN-08003: starting partial resync of recovery catalog

RMAN-08005: partial resync complete

RMAN-03023: executing command: backup

RMAN-08008: channel c1: starting full datafile backupset

RMAN-08502: set_count=5 set_stamp=494177612 creation_time=16-MAY-03

RMAN-08010: channel c1: specifying datafile(s) in backupset

RMAN-08522: input datafile fno=00003 name=D:\ORACLE\ORADATA\TEST\USER01.DBF

RMAN-08013: channel c1: piece 1 created

RMAN-08503: piece handle=D:\BACKUP\TSUSER_05EN93AC_5_1 comment=NONE

RMAN-08525: backup set complete, elapsed time: 00:00:01

RMAN-03023: executing command: partial resync

RMAN-08003: starting partial resync of recovery catalog

RMAN-08005: partial resync complete

RMAN-03022: compiling command: release

RMAN-03023: executing command: release

RMAN-08031: released channel: c1

RMAN>

 

3、继续在测试表中插入记录

SQL> insert into test values(2);

1 row inserted

SQL> commit;

Commit complete

SQL> select * from test;

                         A

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

                         1

                         2

SQL> alter system switch logfile;

System altered.

SQL>r

1* alter system switch logfile;

System altered.

 

4、关闭数据库,模拟丢失数据文件

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down

 

C:\>del D:\ORACLE\ORADATA\TEST\USER01.DBF

 

5、启动数据库,检查错误

SQL> startup

ORACLE instance started.

Total System Global Area  102020364 bytes

Fixed Size                    70924 bytes

Variable Size              85487616 bytes

Database Buffers           16384000 bytes

Redo Buffers                  77824 bytes

Database mounted.

ORA-01157: cannot identify/lock data file 3 - see DBWR trace file

ORA-01110: data file 3: 'D:\ORACLE\ORADATA\TEST\USER01.DBF'

 

6、先打开数据库

SQL> alter database datafile 3 offline drop;

Database altered.

SQL> alter database open;

Database altered.

 

7、恢复该表空间

恢复脚本可以是恢复单个数据文件

run{

allocate channel c1 type disk;

restore datafile 3;

recover datafile 3;

sql 'alter database datafile 3 online';

release channel c1;

}

也可以是,恢复表空间

run{

allocate channel c1 type disk;

restore tablespace users;

recover tablespace users;

sql 'alter database datafile 3 online';

release channel c1;

}

过程如下:

C:\>rman

Recovery Manager: Release 8.1.6.0.0 - Production

RMAN> connect rcvcat rman/rman@back

RMAN-06008: connected to recovery catalog database

RMAN> connect target internal/virpure

RMAN-06005: connected to target database: TEST (DBID=1788174720)

 

RMAN> run{

2> allocate channel c1 type disk;

3> restore datafile 3;

4> recover datafile 3;

5> sql 'alter database datafile 3 online';

6> release channel c1;

7> }

 

RMAN-03022: compiling command: allocate

RMAN-03023: executing command: allocate

RMAN-08030: allocated channel: c1

RMAN-08500: channel c1: sid=13 devtype=DISK

RMAN-03022: compiling command: restore

RMAN-03022: compiling command: IRESTORE

RMAN-03023: executing command: IRESTORE

RMAN-08016: channel c1: starting datafile backupset restore

RMAN-08502: set_count=5 set_stamp=494177612 creation_time=16-MAY-03

RMAN-08089: channel c1: specifying datafile(s) to restore from backup set

RMAN-08523: restoring datafile 00003 to D:\ORACLE\ORADATA\TEST\USER01.DBF

RMAN-08023: channel c1: restored backup piece 1

RMAN-08511: piece handle=D:\BACKUP\TSUSER_05EN93AC_5_1 tag=TSUSER params=NULL

RMAN-08024: channel c1: restore complete

RMAN-03023: executing command: partial resync

RMAN-08003: starting partial resync of recovery catalog

RMAN-08005: partial resync complete

RMAN-03022: compiling command: recover

RMAN-03022: compiling command: recover(1)

RMAN-03022: compiling command: recover(2)

RMAN-03022: compiling command: recover(3)

RMAN-03023: executing command: recover(3)

RMAN-08054: starting media recovery

RMAN-03022: compiling command: recover(4)

RMAN-06050: archivelog thread 1 sequence 332 is already on disk as file D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00332.ARC

RMAN-06050: archivelog thread 1 sequence 333 is already on disk as file D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00333.ARC

RMAN-06050: archivelog thread 1 sequence 334 is already on disk as file D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00334.ARC

RMAN-03023: executing command: recover(4)

RMAN-08515: archivelog filename=D:\ORACLE\ORADATA\TEST\ARCHIVE\TESTT001S00332.ARC thread=1 sequence=332

RMAN-08055: media recovery complete

RMAN-03022: compiling command: sql

RMAN-06162: sql statement: alter database datafile 3 online

RMAN-03023: executing command: sql

RMAN-03022: compiling command: release

RMAN-03023: executing command: release

RMAN-08031: released channel: c1

RMAN>

 

8、检查数据是否完整

SQL> alter database open;

Database altered.

 

SQL> select * from test;

                         A

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

                         1

                         2

说明:

1RMAN也可以实现单个表空间或数据文件的恢复,恢复过程可以在mount下或open方式下,如果在open方式下恢复,可以减少down机时间

2、如果损坏的是一个数据文件,建议offline并在open方式下恢复

3、这里可以看到,RMAN进行数据文件与表空间恢复的时候,代码都比较简单,而且能保证备份与恢复的可靠性,所以建议采用RMAN的备份与恢复

4.3丢失多个数据文件,实现整个数据库的恢复

4.3.1 OS备份方案

OS备份归档模式下损坏(丢失)多个数据文件,进行整个数据库的恢复

1、连接数据库,创建测试表并插入记录

SQL*Plus: Release 8.1.6.0.0 - Production on Tue May 6 13:46:32 2003

(c) Copyright 1999 Oracle Corporation.  All rights reserved.

SQL> connect internal/password as sysdba;

Connected.

 

SQL> create table test(a int);

Table created

SQL> insert into test values(1);

1 row inserted

SQL> commit;

Commit complete

 

2、备份数据库,备份除临时数据文件后的所数据文件

SQL> @hotbak.sql 或在DOS svrmgrl @hotbak.sql

 

3、继续在测试表中插入记录

SQL> insert into test values(2);

1 row inserted

SQL> commit;

Commit complete

SQL> select * from test;

                         A

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

                         1

                         2

SQL> alter system switch logfile;

System altered.

SQL> alter system switch logfile;

System altered.

 

4、关闭数据库,模拟丢失数据文件

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down

 

C:\>del D:\ORACLE\ORADATA\TEST\SYSTEM01.DBF

C:\>del D:\ORACLE\ORADATA\TEST\INDX01.DBF

C:\>del D:\ORACLE\ORADATA\TEST\TOOLS01.DBF

C:\>del D:\ORACLE\ORADATA\TEST\RBS01.DBF

模拟媒体毁坏(这里删除多个数据文件)

 

5、启动数据库,检查错误

SQL> STARTUP

ORACLE instance started.

Total System Global Area  102020364 bytes

Fixed Size                    70924 bytes

Variable Size              85487616 bytes

Database Buffers           16384000 bytes

Redo Buffers                  77824 bytes

Database mounted.

ORA-01157: cannot identify/lock data file 1 - see DBWR trace file

ORA-01110: data file 1: 'D:\ORACLE\ORADATA\TEST\SYSTEM01.DBF'

 

详细信息可以查看报警文件

ORA-1157 signalled during: ALTER DATABASE OPEN...

Thu May 08 09:39:36 2003

Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:

ORA-01157: cannot identify/lock data file 1 - see DBWR trace file

ORA-01110: data file 1: 'D:\ORACLE\ORADATA\TEST\SYSTEM01.DBF'

ORA-27041: unable to open file

OSD-04002: unable to open file

O/S-Error: (OS 2) 系统找不到指定的文件。

 

Thu May 08 09:39:36 2003

Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:

ORA-01157: cannot identify/lock data file 2 - see DBWR trace file

ORA-01110: data file 2: 'D:\ORACLE\ORADATA\TEST\RBS01.DBF'

ORA-27041: unable to open file

OSD-04002: unable to open file

O/S-Error: (OS 2) 系统找不到指定的文件。

 

Thu May 08 09:39:36 2003

Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:

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

ORA-01110: data file 5: 'D:\ORACLE\ORADATA\TEST\TOOLS01.DBF'

ORA-27041: unable to open file

OSD-04002: unable to open file

O/S-Error: (OS 2) 系统找不到指定的文件。

 

Thu May 08 09:39:36 2003

Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:

ORA-01157: cannot identify/lock data file 6 - see DBWR trace file

ORA-01110: data file 6: 'D:\ORACLE\ORADATA\TEST\INDX01.DBF'

ORA-27041: unable to open file

OSD-04002: unable to open file

O/S-Error: (OS 2) 系统找不到指定的文件。

 

通过查询v$recover_file可以看到

SQL> select * from v$recover_file;

 

     FILE# ONLINE  ERROR                 CHANGE# TIME

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

         1 ONLINE  FILE NOT FOUND              0

         2 ONLINE  FILE NOT FOUND              0

         5 ONLINE  FILE NOT FOUND              0

         6 ONLINE  FILE NOT FOUND              0

有四个数据文件需要恢复

 ( 未完,见  (piner) ORACLE备份&恢复案例 3)


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