六、恢复备库

6.2、在主库执行，利用auxiliary来恢复备库

[oracle@rac1 ~]$ $ORACLE_HOME/bin/rman target / auxiliary sys/6212327@standby

RMAN> run

{

allocate channel c1 device type disk format '/soft/backup/%U' connect sys/6212327@rac1;

allocate channel c2 device type disk format '/soft/backup/%U' connect sys/6212327@rac2;

allocate auxiliary channel ac1 device type disk format '/soft/backup/%U';

allocate auxiliary channel ac2 device type disk format '/soft/backup/%U';

duplicate target database for standby;

}

从日志可以看到，oracle先根据参数文件把控制文件恢复到合适位置，然后再根据db_file_name_cover把数据文件恢复到合适位置。

七、后续工作

7.1、把备库至于恢复状态：

[oracle@standby admin]$ sqlplus "/as sysdba"

SQL> alter database recover managed standby database disconnect from session;

Database altered

此时观察备库的alert文件，可以发现有很多类似的信息：

Errors in file /opt/oracle/admin/rac/bdump/rac1_mrp0_10825.trc:

ORA-00313: open failed for members of log group 4 of thread 2

ORA-00312: online log 4 thread 2: '/soft/oradata/rac/raw11'

ORA-27037: unable to obtain file status

Linux Error: 2: No such file or directory

Additional information: 3

Clearing online redo logfile 4 /soft/oradata/rac/raw11

Clearing online log 4 of thread 2 sequence number 50

这是正常的，在第一次置于recover状态的时候，备库会生成对应的online redo log。

7.2、在备库添加standby redo log

Standby redo log比archivelog方式有更大的优势，且在最大保护、最大可用、实时恢复的情况下必须有standby redo log。

Standby redo log的组数一般为(N +1)* thread# （N分别为每个thread#的联机日志组数）。在本例，每一个thread的联机日志都是2组，所以，需要添加6组standby redo log：

SQL> alter database recover managed standby database cancel;

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 1 ('/soft/oradata/rac/slog4.ora') SIZE 52428800;

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 1 ('/soft/oradata/rac/slog5.ora') SIZE 52428800;

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 1 ('/soft/oradata/rac/slog6.ora') SIZE 52428800;

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 2 ('/soft/oradata/rac/slog7.ora') SIZE 52428800;

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 2 ('/soft/oradata/rac/slog8.ora') SIZE 52428800;

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 2 ('/soft/oradata/rac/slog9.ora') SIZE 52428800;

注意：standby redo log的大小必须和联机日志一样。

八、遇到的问题

8.1、FAL[client, MRP0]: Error 12545 connecting to PRIMARY for fetching gap sequence

Wed Apr 30 20:21:23 2008

Errors in file /opt/oracle/admin/rac/bdump/rac1_mrp0_10965.trc:

ORA-12545: Connect failed because target host or object does not exist

Wed Apr 30 20:22:23 2008

FAL[client]: Failed to request gap sequence

GAP - thread 1 sequence 88-88

DBID 2232067446 branch 644085430

FAL[client]: All defined FAL servers have been attempted.

这个问题和gap有关，备库尝试拿gap的时候，发现不能连接主库。这个问题是RAC的监听造成的，参考yangtingkun的解决方法，修改两个参数 即可：

ALTER SYSTEM SET LOCAL_LISTENER = '(ADDRESS = (PROTOCOL = TCP)(HOST = 200.200.200.11)(PORT = 1521))' SID = 'rac1';

ALTER SYSTEM SET LOCAL_LISTENER = '(ADDRESS = (PROTOCOL = TCP)(HOST = 200.200.200.22)(PORT = 1521))' SID = 'rac2';

8.2

FAL[client]: Failed to request gap sequence

GAP - thread 1 sequence 88-88

DBID 2232067446 branch 644085430

FAL[client]: All defined FAL servers have been attempted.

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

Check that the CONTROL_FILE_RECORD_KEEP_TIME initialization

parameter is defined to a value that is sufficiently large

enough to maintain adequate log switch information to resolve

archivelog gaps.

这个问题还是和gap有关。备库现在需要从主库上拿sequence 88这个归档，但这个归档在前面做备份的时候删除了。解决方法是从备份还原这个归档：

RMAN> restore archivelog sequence 88;