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What are the three different situations in which RAC controls file recovery? aiming at this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

RAC controls file recovery (three different situations)

Test environment:

System: LINUX-64

Database: 10.2.0.1

Two-node RAC (RACDB1,RACDB2), ASM for storage

In the case of backup, if the control file is lost, how can we restore it?

One: use the backup control file to restore, and finally need to use resetlogs to open.

(1) backup control files

RMAN > backup current controlfile

(2) switch logs and modify data

RACDB1 > alter system switch logfile

System altered.

RACDB1 > create table test2 as select * from dba_users

Table created.

RACDB1 > alter system switch logfile

System altered.

RACDB1 > SELECT thread#,group#,sequence#,status FROM V$log

THREAD# GROUP# SEQUENCE# STATUS

--

1 1 5 ACTIVE

1 2 6 CURRENT

2 3 3 CURRENT

2 4 2 INACTIVE

1 5 4 INACTIVE

(3) close the database and delete the control file

RACDB1 > shutdown abort

RACDB2 > shutdown abort

ASMCMD > pwd

+ rac_disk/racdb/controlfile

ASMCMD > ls

Current.256.794232615

ASMCMD > rm *

(4) start the database and have no control files, so you can only go to nomount.

RACDB1 > startup

ORACLE instance started.

Total System Global Area 184549376 bytes

Fixed Size 2019448 bytes

Variable Size 142610312 bytes

Database Buffers 37748736 bytes

Redo Buffers 2170880 bytes

ORA-00205: error in identifying control file, check alert log for more info

(5) restore control files

RMAN > restore controlfile from'+ RAC_DISK/racdb/backupset/2012_09_28/ncnnf0_tag20120928t003933_0.272.795141579'

RACDB1 > alter database mount

Database altered.

RACDB1 > SELECT thread#,group#,sequence#,status FROM V$log

THREAD# GROUP# SEQUENCE# STATUS

--

1 1 2 CURRENT

1 2 0 UNUSED

1 5 1 INACTIVE

2 4 0 UNUSED

2 3 1 CURRENT

(6) restore the database

First use auto to restore to the current online log, oracle will prompt that the archive cannot be found, and you need to enter the online log manually. As follows:

RACDB1 > recover database using backup controlfile

ORA-00279: change 1185078 generated at 09/28/2012 00:40:37 needed for thread 1

ORA-00289: suggestion: + RAC_DISK/racdb/flashback/1_6_795092359.dbf

ORA-00280: change 1185078 for thread 1 is in sequence # 6

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

+ rac_disk/racdb/onlinelog/group_2.258.794232619-enter the current online log of RACDB1

ORA-00279: change 1185078 generated at 09/28/2012 00:40:10 needed for thread 2

ORA-00289: suggestion: + RAC_DISK/racdb/flashback/2_2_795092359.dbf

ORA-00280: change 1185078 for thread 2 is in sequence # 2

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

+ rac_disk/racdb/onlinelog/group_4.266.794234285-this is not RACDB2's current online log, but you can actually enter an archive.

ORA-00279: change 1185082 generated at 09/28/2012 00:40:38 needed for thread 2

ORA-00289: suggestion: + RAC_DISK/racdb/flashback/2_3_795092359.dbf

ORA-00280: change 1185082 for thread 2 is in sequence # 3

ORA-00278: log file'+ rac_disk/racdb/onlinelog/group_4.266.794234285' no longer

Needed for this recovery

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

+ rac_disk/racdb/onlinelog/group_3.265.794234279-- this is RACDB2's current online log

Log applied.

Media recovery complete.

Summary: in RAC environment, the online log of each node must be used when you want to use current online log.

(7) Open the database in resetlogs mode.

RACDB1 > alter database open resetlogs

Database altered.

RACDB2 > startup

ORACLE instance started.

Total System Global Area 184549376 bytes

Fixed Size 2019448 bytes

Variable Size 138416008 bytes

Database Buffers 41943040 bytes

Redo Buffers 2170880 bytes

Database mounted.

Database opened.

RACDB1 > select count (*) from test2

COUNT (*)

-

eleven

Second, using noresetlogs method to reconstruct the control file.

(1) backup control files

RMAN > backup current controlfile

(2) switch between log and operation data

RACDB1 > alter system switch logfile

System altered.

RACDB1 > create table test3 as select * from dba_data_files

Table created.

RACDB1 > alter system switch logfile

System altered.

(3) close the database and delete the control file

RACDB1 > shutdown abort

RACDB2 > shutdown abort

ASMCMD > pwd

+ rac_disk/racdb/controlfile

ASMCMD > ls

Current.256.795142367

ASMCMD > rm *

RACDB1 > startup

ORACLE instance started.

Total System Global Area 184549376 bytes

Fixed Size 2019448 bytes

Variable Size 146804616 bytes

Database Buffers 33554432 bytes

Redo Buffers 2170880 bytes

ORA-00205: error in identifying control file, check alert log for more info

(4) restore control files

RMAN > restore controlfile from'+ RAC_DISK/racdb/backupset/2012_09_28/ncnnf0_tag20120928t015109_0.285.795145873'

RACDB1 > alter database mount

Database altered.

RACDB1 > alter database backup controlfile to trace;-back up the control file to the trace file

Database altered.

(5) reconstruct the control file.

RACDB1 > shutdown immediate

Delete the control file.

RACDB1 > startup nomount

(6) reconstruct the control file by noresetlogs

Since it is a RAC environment, the following parameters need to be modified first:

If you do not modify the parameters, the error is as follows:

ORA-01503: CREATE CONTROLFILE failed

ORA-12720: operation requires database is in EXCLUSIVE mode

RACDB1 > alter system set cluster_database=FALSE scope=spfile sid='*'

System altered.

RACDB1 > shutdown immediate

ORA-01507: database not mounted

ORACLE instance shut down.

RACDB1 > startup nomount

ORACLE instance started.

Total System Global Area 184549376 bytes

Fixed Size 2019448 bytes

Variable Size 146804616 bytes

Database Buffers 33554432 bytes

Redo Buffers 2170880 bytes

CREATE CONTROLFILE REUSE DATABASE "RACDB" NORESETLOGS ARCHIVELOG

MAXLOGFILES 192

MAXLOGMEMBERS 3

MAXDATAFILES 1024

MAXINSTANCES 32

MAXLOGHISTORY 292

LOGFILE

GROUP 1 (

'+ RAC_DISK/racdb/onlinelog/group_1.257.795091225'

'+ RAC_DISK/racdb/onlinelog/group_1.295.795091229'

) SIZE 50m

GROUP 2'+ RAC_DISK/racdb/onlinelog/group_2.258.794232619' SIZE 50m

GROUP 3'+ RAC_DISK/racdb/onlinelog/group_3.265.794234279' SIZE 50m

GROUP 4'+ RAC_DISK/racdb/onlinelog/group_4.266.794234285' SIZE 50m

GROUP 5 (

'+ RAC_DISK/racdb/onlinelog/group_5.269.795092365'

'+ RAC_DISK/racdb/onlinelog/group_5.296.795092369'

) SIZE 100m

-- STANDBY LOGFILE

DATAFILE

'+ RAC_DISK/racdb/datafile/system.259.794232627'

'+ RAC_DISK/racdb/datafile/undotbs1.260.794232647'

'+ RAC_DISK/racdb/datafile/sysaux.261.794232657'

'+ RAC_DISK/racdb/datafile/undotbs2.263.794232675'

'+ RAC_DISK/racdb/datafile/users.264.794232683'

CHARACTER SET ZHS16GBK

twenty-seven

CREATE CONTROLFILE REUSE DATABASE "RACDB" NORESETLOGS ARCHIVELOG

*

ERROR at line 1:

ORA-01503: CREATE CONTROLFILE failed

ORA-01276: Cannot add file + RAC_DISK/racdb/controlfile/current.256.795146237.

File has an Oracle Managed Files file name. -- because you use OMF, you need to comment out controlfile in the parameter file first.

RACDB1 > show parameter control_files

NAME TYPE VALUE

-

Control_files string + RAC_DISK/racdb/controlfile/cu

Rrent.256.795146237

RACDB1 > alter system set control_files=false scope=spfile sid='*'

System altered.

RACDB1 > alter system reset control_files scope=spfile sid='*'

System altered.

RACDB1 > shutdown immediate

ORA-01507: database not mounted

ORACLE instance shut down.

RACDB1 > startup nomount

ORACLE instance started.

Total System Global Area 184549376 bytes

Fixed Size 2019448 bytes

Variable Size 146804616 bytes

Database Buffers 33554432 bytes

Redo Buffers 2170880 bytes

RACDB1 > show parameter control_files

NAME TYPE VALUE

-

Control_files string / u01/app/oracle/product/10.2.0

/ db_1/dbs/cntrlRACDB1.dbf

CREATE CONTROLFILE REUSE DATABASE "RACDB" NORESETLOGS ARCHIVELOG

MAXLOGFILES 192

MAXLOGMEMBERS 3

MAXDATAFILES 1024

MAXINSTANCES 32

MAXLOGHISTORY 292

LOGFILE

GROUP 1 (

'+ RAC_DISK/racdb/onlinelog/group_1.257.795091225'

'+ RAC_DISK/racdb/onlinelog/group_1.295.795091229'

) SIZE 50m

GROUP 2'+ RAC_DISK/racdb/onlinelog/group_2.258.794232619' SIZE 50m

GROUP 3'+ RAC_DISK/racdb/onlinelog/group_3.265.794234279' SIZE 50m

GROUP 4'+ RAC_DISK/racdb/onlinelog/group_4.266.794234285' SIZE 50m

GROUP 5 (

'+ RAC_DISK/racdb/onlinelog/group_5.269.795092365'

'+ RAC_DISK/racdb/onlinelog/group_5.296.795092369'

) SIZE 100m

-- STANDBY LOGFILE

DATAFILE

'+ RAC_DISK/racdb/datafile/system.259.794232627'

'+ RAC_DISK/racdb/datafile/undotbs1.260.794232647'

'+ RAC_DISK/racdb/datafile/sysaux.261.794232657'

'+ RAC_DISK/racdb/datafile/undotbs2.263.794232675'

'+ RAC_DISK/racdb/datafile/users.264.794232683'

CHARACTER SET ZHS16GBK

27

Control file created.

RACDB1 > RACDB1 > show parameter control_files

NAME TYPE VALUE

-

Control_files string + RAC_DISK/racdb/controlfile/cu

Rrent.256.795147383, + RAC_DISK

/ racdb/controlfile/current.279

. 795147383

RACDB1 > alter system set cluster_database=true scope=spfile sid='*';-Don't forget

System altered.

(7) restore the database

RACDB1 > recover database

ORA-00279: change 1185480 generated at 09/28/2012 01:45:00 needed for thread 1

ORA-00289: suggestion: + RAC_DISK/racdb/flashback/1_1_795145477.dbf

ORA-00280: change 1185480 for thread 1 is in sequence # 1

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

Auto

Log applied.

Media recovery complete.

(8) Open the database

RACDB1 > alter database open

Database altered.

Third, use the resetlogs method to reconstruct the control file. The recovery process in this method is similar to the control file that uses a backup. There is no narrative here. Finally, you also need to use resetlogs to open it.

It is worth noting that the difference between the two reconstruction methods of create controlfile resetlogs/noresetlogs is that when noresetlogs rebuilds the control file, the datafile checkpoint in the control file comes from the current log header in online logs. When the control file is reconstructed with resetlogs, the datafile checkpoint in the control file comes from each data file header.

The answers to the questions about what are the three different situations of RAC control file recovery are shared here. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel for more related knowledge.

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