Oracle Physical Dataguard环境使用RMAN备份和恢复

 

                  Oracle Physical Dataguard环境使用RMAN备份和恢复

      由于Physical Dataguard使用的是块恢复技术来保持和PRIMARY的一致性，因此可以在STANDBY
上进行rman备份，从而减轻PRIMARY的压力.当PRIMARY出现数据库故障时，可以使用在STANDBY上
的备份来进行恢复.

先决条件：需要配置catalog.

在PRIMARY上以catalog方式连接，并且注册数据库

[oracle@PRIMARY admin]$ $ORACLE_HOME/bin/rman target / catalog

> register database;

database registered in recovery catalog
starting full resync of recovery catalog
full resync complete

RMAN> configure db_unique_name CP connect identifier 'cp';

new RMAN configuration parameters:
CONFIGURE DB_UNIQUE_NAME 'cp' CONNECT IDENTIFIER  'cp';
new RMAN configuration parameters are successfully stored
starting full resync of recovery catalog
full resync complete

RMAN> configure db_unique_name cepstby connect identifier 'cepstby';

new RMAN configuration parameters:
CONFIGURE DB_UNIQUE_NAME 'cepstby' CONNECT IDENTIFIER  'cepstby';
new RMAN configuration parameters are successfully stored
starting full resync of recovery catalog
full resync complete

查看已注册的数据库信息，rman自动识别数据库角色等信息.

RMAN> list db_unique_name of database;

List of Databases
DB Key  DB Name  DB ID            Database Role    Db_unique_name
------- ------- ----------------- ---------------  ------------------
1       CP    2894644313       PRIMARY          CP              
1       CP    2894644313       STANDBY          CEPSTBY 

 

rman 连接到STANDBY的target进行备份

[oracle@standby ~]$ $ORACLE_HOME/bin/rman target / catalog 

Manager: Release 11.1.0.7.0 - Production on Sat Mar 26 10:52:00 2016

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: CP (DBID=2894644313, not open)
connected to recovery catalog database

在standby上执行备份操作.
RMAN> run
2> {
3> allocate channel c2 device type disk;
4> backup as backupset database format '/home/oracle/%U';
5> release channel c2;
6> }

allocated channel: c2
channel c2: SID=1085 device type=DISK

Starting backup at 26-MAR-16
Starting implicit crosscheck backup at 26-MAR-16
Finished implicit crosscheck backup at 26-MAR-16

.............................

我们通过在主库移动文件来摸拟数据文件被破坏的情形

[oracle@primary]$ mv /u01/app/oracle/oradata/cp/users01.dbf /u01/app/oracle/oradata/cp/oldusers01.dbf

DONGDONGTANG> startup;
ORACLE instance started.

Total System Global Area 1135747072 bytes
Fixed Size      2158992 bytes
Variable Size    822087280 bytes
Database Buffers   301989888 bytes
Redo Buffers      9510912 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/cp/users01.dbf'

 

接下来我们要做的是从备库上复制相关备份文件到主库中
[oracle@standby ~]$ scp /home/oracle/0* 192.168.56.21:/home/oracle/bak

在主库中对相关文件进行catalog

[oracle@PRIMARY admin]$ $ORACLE_HOME/bin/rman target / catalog

Manager: Release 11.1.0.7.0 - Production on Sat Mar 26 10:56:56 2016

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: CP (DBID=2894644313, not open)
connected to recovery catalog database

RMAN> catalog start with '/home/oracle/bak';

searching for all files that match the pattern /home/oracle/bak

List of Files Unknown to the Database
=====================================
File Name: /home/oracle/bak/09r1eku6_1_1
File Name: /home/oracle/bak/08r1ekse_1_1

Do you really want to catalog the above files (enter YES or NO)? yes
cataloging files...
cataloging done

List of Cataloged Files
=======================
File Name: /home/oracle/bak/09r1eku6_1_1
File Name: /home/oracle/bak/08r1ekse_1_1

现在可以发现4号文件的相关备份信息
RMAN> list backup of datafile 4;

List of Backup Sets
===================

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
111     Full    1.08G      DISK        00:00:53     26-MAR-16     
        BP Key: 176   Status: AVAILABLE  Compressed: NO  Tag: TAG20160326T105302
        PRIMARYece Name: /home/oracle/bak/08r1ekse_1_1
  List of Datafiles in backup set 111
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  4       Full 927757     26-MAR-16 /u01/app/oracle/oradata/cp/users01.dbf

恢复/u01/app/oracle/oradata/cp/users01.dbf文件

RMAN> run
{
allocate channel c1 device type disk;
restore datafile 4;
recover datafile 4;
release channel c1;
}2> 3> 4> 5> 6> 7>

allocated channel: c1
channel c1: SID=1090 device type=DISK

Starting restore at 26-MAR-16

channel c1: starting datafile backup set restore
channel c1: specifying datafile(s) to restore from backup set
channel c1: restoring datafile 00004 to /u01/app/oracle/oradata/cp/users01.dbf
channel c1: reading from backup PRIMARYece /home/oracle/bak/08r1ekse_1_1
channel c1: PRIMARYece handle=/home/oracle/bak/08r1ekse_1_1 tag=TAG20160326T105302
channel c1: restored backup PRIMARYece 1
channel c1: restore complete, elapsed time: 00:00:03
Finished restore at 26-MAR-16

Starting recover at 26-MAR-16

starting media recovery
media recovery complete, elapsed time: 00:00:01

Finished recover at 26-MAR-16

released channel: c1

再次尝试打开数据库.
....................
Variable Size    822087280 bytes
Database Buffers   301989888 bytes
Redo Buffers      9510912 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/cp/users01.dbf'

DONGDONGTANG> alter database open;

Database altered.

DONGDONGTANG> select name,status from v$datafile where file#=4;

NAME
--------------------------------------------------------------------------------
STATUS
-------
/u01/app/oracle/oradata/cp/users01.dbf
ONLINE

主数据库已经可以成功打开.