oracle增量恢复解决备库GAP问题

Rolling forward a standby database using RMAN Incremental Backup.

模拟归档丢失的情况

一主库操作：

查看当前归档

停用归档传输

alter system set log_archive_dest_state_2=defer;

切换归档

alter system switch logfile;

模拟丢失归档

RMAN> delete archivelog low sequence 3821 high sequence 3823;

RMAN> delete force archivelog low sequence 3821 high sequence 3823; ------11G需要添加force

恢复归档传输

alter system set log_archive_dest_state_2=enable;

备库警告日志错误

FAL[client]: Failed to request gap sequence

GAP - thread 1 sequence 79-81

DBID 2144245355 branch 846098926

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.

Tue Apr 29 18:54:21 2014

二备库操作

用增量备份解决断档

备库查询当前scn号

--停止mrp应用

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

--查询scn取最小值（取当前scn和最小scn的中的最小值）

SELECT CURRENT_SCN FROM V$DATABASE;

SELECT to_char(CURRENT_SCN) FROM V$DATABASE;

CURRENT_SCN

570778

select min(fhscn) from x$kcvfh;

MIN(FHSCN)

570778

三增量备份

主库进行增量备份并创建controlfile

RMAN>BACKUP INCREMENTAL FROM SCN 570778 DATABASE FORMAT '/tmp/ForStandby_%U' tag 'FORSTANDBY';

scp ForStandby_* node2:/oracle/arch/

ALTER DATABASE CREATE STANDBY CONTROLFILE AS '/tmp/control01.ctl';

scp control01.ctl node2:/oracle/oradata/test/control01.ctl

在主库增量备份的过程中，可使用以下语句查询进度

SELECT inst_id,

sid,

serial#,

opname,

ROUND(SOFAR / TOTALWORK * 100, 2) "%_COMPLETE"

FROM gV$SESSION_LONGOPS

WHERE OPNAME LIKE 'RMAN%'

AND OPNAME NOT LIKE '%aggregate%'

AND TOTALWORK != 0

AND SOFAR <> TOTALWORK;

最后确定主库在此scn后是否添加过数据文件

SQL> select FILE#,name from v$datafile where CREATION_CHANGE#> =570778;

如果有添加过数据文件，确保standby_file_management=auto，则后续可以restore进行恢复

如果不使用restore进行恢复，则使用以下步骤进行创建数据文件（待验证）

select file#,name from v$datafile;

alter database create datafile '/oracle/app/product/11.2.0/db_1/dbs/UNNAMED00011' as '/oradata/ddd01.dbf'

备库端操作

关闭数据库用新的controlfile打开到mount状态并注册备份信息

恢复数据文件：

alter database mount;

RMAN>CATALOG BACKUPPIECE '/oracle/arch/ForStandby_04p6vfe9_1_1';

RMAN>CATALOG BACKUPPIECE '/oracle/arch/ForStandby_03p6vfdg_1_1';

或

RMAN> catalog start with '/oracle/arch';

恢复数据文件：（如果有增加过数据文件，执行这步，没有跳到下一步）

RMAN> restore datafile 10;数据文件号为在主库scn添加过的数据文件号

恢复

RMAN> RECOVER DATABASE NOREDO;

备库开启mrp

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;

关闭mrp

alter database recover managed standby database cancel;

开启数据库

alter database open

四补充

若主库的部分归档由于某些原因没有传至备库，则可通过以下方法解决：

1 主库scp 备库丢失的归档备库

2 备库应用归档：

alter database register logfile '/data/archlog /1_324_966768650.dbf';

3 观察alert日志