ORACLE DATAGUARD遇到GAP增量恢复方式修复RAC环境备机的实践

ORACLE DATAGUARD技术是一个常用的数据保护机制，在DATAGUARD运行过程中，遇到异常导致备机不同步，而主库的归档日志也被清理，此时出现GAP，无法同步；就需要人工处理；对于小型数据库重新全量同步数据即可，但是对于大型数据库，通常建议是增量方式恢复，减少时间精力、网络、磁盘等资源的消耗，如下为一个RAC环境的备机增量恢复的过程：

1.查询备库SCN号及主备库数据文件信息
备库操作，备库取消归档应用，查询最小SCN号
SQL> select min(checkpoint_change#) from v$datafile_header
where file# not in (select file# from v$datafile where enabled = 'READ ONLY');
MIN(F.FHSCN)
----------------
75039049863

生产

SQL> select to_char(current_scn) from v$database;

SQL> select min(fhscn) from x$kcvfh;

SQL> select min(f.fhscn) from x$kcvfh f,v$datafile d where f.hxfil=d.file# and d.enabled!='READ ONLY';

备库----------------------------------------------

SQL> select to_char(current_scn) from v$database;

SQL>  select min(fhscn) from x$kcvfh;

SQL> select min(f.fhscn) from x$kcvfh f,v$datafile d where f.hxfil=d.file# and d.enabled!='READ ONLY';

查完后查看最小值

查询主备库数据文件个数是否一致并记录备库数据文件路径
select file#, name from v$datafile order by file# ;

2. 主库做RMAN的增量备份，scn号为查询出来的备库最小scn号
[oracle@his01 rmanbak]$ cat rman.sh 
#!/bin/bash

# BACKUP_PATH=/backup/rman_backup/

# mkdir $BACKUP_PATH

source /home/oracle/.bash_profile

rman target / << EOF

run{
allocate channel d1 type disk;
allocate channel d2 type disk;
backup as compressed backupset datafile 60,61 format '/home/oracle/zlback/datafile_%U.bak' tag 'datafile';------若主库比备库多两个数据文件，执行这条命令。
BACKUP as compressed INCREMENTAL FROM SCN 75039049863 DATABASE FORMAT '/backup/hisbak/rmanbak/ForStandby_%U' tag 'FORSTANDBY';-----as compressed 为压缩参数
release channel d1;
release channel d2;
}

3.将备份好的备份集scp到备库
[oracle@his01 rmanbak]$ scp ForStandby_i* 192.168.10.35:/rmanbak/

4.备库注册备份集
RMAN> catalog start with '/rmanbak/';

using target database control file instead of recovery catalog
searching for all files that match the pattern /rmanbak/

List of Files Unknown to the Database
=====================================
File Name: /rmanbak/ForStandby_ic3kr2p0_38476_1_1
File Name: /rmanbak/ForStandby_ib3kr1ok_38475_1_1
File Name: /rmanbak/ForStandby_ia3kr1ok_38474_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: /rmanbak/ForStandby_ic3kr2p0_38476_1_1
File Name: /rmanbak/ForStandby_ib3kr1ok_38475_1_1
File Name: /rmanbak/ForStandby_ia3kr1ok_38474_1_1

5.使用增量备份集恢复备库
RMAN> recover database noredo;

Starting recover at 20-MAR-2025 20:14:28
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=304 instance=hisdb1 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=908 instance=hisdb1 device type=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: SID=2570 instance=hisdb1 device type=DISK
allocated channel: ORA_DISK_4
channel ORA_DISK_4: SID=3174 instance=hisdb1 device type=DISK
channel ORA_DISK_1: starting incremental datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
destination for restore of datafile 00001: +DATADG/hisdb/datafile/system01.dbf
destination for restore of datafile 00002: +DATADG/hisdb/datafile/sysaux01.dbf
……
destination for restore of datafile 00074: +DATADG/hisdb/datafile/portal_his.366.1186787373
destination for restore of datafile 00077: +DATADG/hisdb/datafile/portal_his.369.1186787431
destination for restore of datafile 00080: +DATADG/hisdb/datafile/undotbs2.396.1195663885
channel ORA_DISK_1: reading from backup piece /rmanbak/ForStandby_ia3kr1ok_38474_1_1
channel ORA_DISK_2: starting incremental datafile backup set restore
channel ORA_DISK_2: specifying datafile(s) to restore from backup set
destination for restore of datafile 00008: +DATADG/hisdb/datafile/sysaux04.dbf
destination for restore of datafile 00009: +DATADG/hisdb/datafile/portal01.dbf
destination for restore of datafile 00013: +DATADG/hisdb/datafile/portal_his04.dbf
destination for restore of datafile 00015: +DATADG/hisdb/datafile/portal_his06.dbf
destination for restore of datafile 00017: +DATADG/hisdb/datafile/portal_his08.dbf
destination for restore of datafile 00019: +DATADG/hisdb/datafile/portal_his11.dbf
destination for restore of datafile 00021: +DATADG/hisdb/datafile/portal_his13.dbf
destination for restore of datafile 00024: +DATADG/hisdb/datafile/portal_his16.dbf
destination for restore of datafile 00027: +DATADG/hisdb/datafile/portal_his10.dbf
……
destination for restore of datafile 00075: +DATADG/hisdb/datafile/portal_his.367.1186787375
destination for restore of datafile 00076: +DATADG/hisdb/datafile/portal_his.368.1186787429
destination for restore of datafile 00078: +DATADG/hisdb/datafile/portal_his_2025_0208.dbf
destination for restore of datafile 00079: +DATADG/hisdb/datafile/undotbs1.395.1195663875
channel ORA_DISK_2: reading from backup piece /rmanbak/ForStandby_ib3kr1ok_38475_1_1
channel ORA_DISK_2: piece handle=/rmanbak/ForStandby_ib3kr1ok_38475_1_1 tag=FORSTANDBY
channel ORA_DISK_2: restored backup piece 1
channel ORA_DISK_2: restore complete, elapsed time: 00:20:46
channel ORA_DISK_1: piece handle=/rmanbak/ForStandby_ia3kr1ok_38474_1_1 tag=FORSTANDBY
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:28:16

Finished recover at 20-MAR-2025 20:42:46

RMAN> exit

恢复多出来的数据文件
RMAN> catalog backuppiece '/datafile_%U.bak';

RMAN> restore datafile 60,61;

6.恢复控制文件
SYS@hisdb1>shutdown immediate
ORA-01109: database not open

Database dismounted.
ORACLE instance shut down.
SYS@hisdb1>startup nomount
ORACLE instance started.

Total System Global Area 8.1068E+10 bytes
Fixed Size                 37218536 bytes
Variable Size            1.3422E+10 bytes
Database Buffers         6.7377E+10 bytes
Redo Buffers              231215104 bytes

RMAN> restore standby controlfile from '/rmanbak/ForStandby_ic3kr2p0_38476_1_1';

Starting restore at 20-MAR-2025 21:38:01
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=908 instance=hisdb1 device type=DISK

channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:02
output file name=+DATADG/HISDB/CONTROLFILE/current.267.1196261129
Finished restore at 20-MAR-2025 21:38:03

7.catalog datafilecopy
hisdg01:/home/oracle$rman target /

Recovery Manager: Release 19.0.0.0.0 - Production on Thu Mar 20 21:50:41 2025
Version 19.16.0.0.0

Copyright (c) 1982, 2019, Oracle and/or its affiliates.  All rights reserved.

connected to target database: HISDB (DBID=1936455435, not open)

RMAN> catalog datafilecopy '+DATADG/hisdb/datafile/LOGMINER_TBS.261.1145745771';
catalog datafilecopy '+DATADG/hisdb/datafile/LOGMINER_TBS.397.1196189189';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL.278.1145744523';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL.297.1145740519';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL.401.1196189295';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.256.1152206447';

catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.257.1145737777';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.260.1145737775';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.262.1145737777';
……
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.347.1184327183';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.348.1184327185';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.349.1184327263';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.350.1184327263';
catalog datafilecopy '+DATADG/hisdb/datafile/PORTAL_HIS.351.1184327263';
catalog datafilecusing target database control file instead of recovery catalog
cataloged datafile copy
datafile copy file name=+DATADG/hisdb/datafile/logminer_tbs.261.1145745771 RECID=11 STAMP=1196286653
……
catalog datafilecopy '+DATADG/hisdb/datafile/portal_his09.dbf'
cataloged datafile copy
datafile copy file name=+DATADG/hisdb/datafile/portal_his.394.1192550351 RECID=88 STAMP=1196286659

RMAN>
8.SWITCH DATABASE TO COPY;
RMAN> SWITCH DATABASE TO COPY;

datafile 1 switched to datafile copy "+DATADG/hisdb/datafile/system01.dbf"
datafile 2 switched to datafile copy "+DATADG/hisdb/datafile/sysaux01.dbf"
datafile 3 switched to datafile copy "+DATADG/hisdb/datafile/undotbs01.dbf"
……………………
datafile 79 switched to datafile copy "+DATADG/hisdb/datafile/undotbs1.395.1195663875"
datafile 80 switched to datafile copy "+DATADG/hisdb/datafile/undotbs2.396.1195663885"

RMAN>

9.开启MRP进程
SYS@hisdb1>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT USING CURRENT LOGFILE;

Database altered.

SYS@hisdb1>SYS@hisdb1>

PROCESS   STATUS          THREAD#  SEQUENCE#     BLOCK#
--------- ------------ ---------- ---------- ----------
ARCH      CLOSING               2      52552      36864
ARCH      CLOSING               1      59424      51200
RFS       IDLE                  1      59425      24784
RFS       IDLE                  2      52553      44835
RFS       RECEIVING             2      52265     126977
RFS       RECEIVING             2      52264      57345
RFS       RECEIVING             2      52263     436225
RFS       RECEIVING             2      52335      14337
RFS       RECEIVING             2      52334     221185
RFS       RECEIVING             2      52333     348161
MRP0      APPLYING_LOG          2      52262     191805

11 rows selected.

10.第一次增量备份未备份至最新（可通过查找数据文件scn号找出最小scn号）
SYS@hisdb1>select file#,TO_CHAR(checkpoint_change#, 'FM999999999999999999999999')  from v$datafile_header;

     FILE# TO_CHAR(CHECKPOINT_CHANGE
---------- -------------------------
         1 75578048600
         2 75578048600
         3 75578048600
         4 75578048600
         5 75578048600
         6 75578048600
         7 75578048600
         8 75578048600
         9 75578048600
        10 75578048600
        11 75578048600