如何重建RAC的控制文件

在下面的一些情况下，可能需要重建控制文件：

o 所有控制文件都已损坏或丢失
o 没有针对控制文件的备份或者备份已损坏
o 或者在一些情况下，Oracle Support建议这么做

下面是针对RAC环境下重建控制文件的具体过程， 包括两个例子。一个是以noresetlogs模式来重建控制文件，一个是以resetlogs模式来重建控制文件。如果redo logs都存在而且没有被损坏，那么可以采用noresetlogs。 使用resetlogs会将所有redo log清空而且重置log sequence为1.

在RAC上重建控制文件与单实例有一些小区别： 在重建控制文件前必须设置cluster_database=false，而且只启动一个实例来执行操作，否则会报错
ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode

重建完控制文件后，需要再将cluster_database设为true.

TESTCASE1
---------------------------
用noresetlog模式重建控制文件

过程：

1.首先生成重建控制文件的脚本：
SQL> alter database backup controlfile to trace;

Database altered.

2. 所生成的控制文件的脚本会在udump下：

SQL> show parameter user_dump_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
user_dump_dest                       string      /u01/app/oracle/diag/rdbms/racdb/RACDB1/trace

数据库的Alert log中也会详细输出这个文件的路径和名字：
alter database backup controlfile to trace
Backup controlfile written to trace file /u01/app/oracle/diag/rdbms/racdb/RACDB1/trace/RACDB1_ora_10076.trc

（注意： 例子中使用到的具体脚本，比如创建控制文件和添加临时数据文件的命令都在上面生成的trace文件中，其它步骤和命令也基本都在这个trace中）。

3. 停止所有数据库实例：
[oracle@rac1 trace]$ srvctl stop database -d RACDB

4. 用noresetlog重建控制文件：
[oracle@rac1 trace]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Tue Jan 8 11:23:44 2013

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount; <==启动一个实例
ORACLE instance started.

Total System Global Area  739065856 bytes
Fixed Size                  2232032 bytes
Variable Size             549454112 bytes
Database Buffers          184549376 bytes
Redo Buffers                2830336 bytes
SQL> CREATE CONTROLFILE REUSE DATABASE "RACDB" NORESETLOGS  ARCHIVELOG
 2      MAXLOGFILES 192
 3      MAXLOGMEMBERS 3
 4      MAXDATAFILES 1024
 5      MAXINSTANCES 32
 6      MAXLOGHISTORY 292
 7  LOGFILE
 8    GROUP 1 (
 9      '+DATA/racdb/onlinelog/group_1.261.783272805',
10      '+RECO/racdb/onlinelog/group_1.257.783272807'
11    ) SIZE 50M BLOCKSIZE 512,
12    GROUP 2 (
13      '+DATA/racdb/onlinelog/group_2.262.783272807',
14      '+RECO/racdb/onlinelog/group_2.258.783272809'
15    ) SIZE 50M BLOCKSIZE 512,
16    GROUP 3 (
17      '+DATA/racdb/onlinelog/group_3.269.804115405',
18      '+RECO/racdb/onlinelog/group_3.261.804115405'
19    ) SIZE 50M BLOCKSIZE 512,
20    GROUP 4 (
21      '+DATA/racdb/onlinelog/group_4.270.804115405',
22      '+RECO/racdb/onlinelog/group_4.263.804115407'
23    ) SIZE 50M BLOCKSIZE 512
24  -- STANDBY LOGFILE
25  DATAFILE
26    '+DATA/racdb/datafile/system.256.783272707',
27    '+DATA/racdb/datafile/sysaux.257.783272707',
28    '+DATA/racdb/datafile/undotbs1.258.783272707',
29    '+DATA/racdb/datafile/users.259.783272707',
30    '+DATA/racdb/datafile/example.264.783272831',
31    '+DATA/racdb/datafile/undotbs2.265.783273081'
32  CHARACTER SET AL32UTF8
33  ;
CREATE CONTROLFILE REUSE DATABASE "RACDB" NORESETLOGS  ARCHIVELOG
*
ERROR at line 1:
ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode  <============由于没有设置cluster_database=false，所以报错

需要将设置cluster_database=false：
SQL> alter system set cluster_database=false scope=spfile;

System altered.

SQL> shutdown immediate
ORA-01507: database not mounted


ORACLE instance shut down.

SQL> startup nomount;
ORACLE instance started.

Total System Global Area  739065856 bytes
Fixed Size                  2232032 bytes
Variable Size             549454112 bytes
Database Buffers          184549376 bytes
Redo Buffers                2830336 bytes
SQL> CREATE CONTROLFILE REUSE DATABASE "RACDB" NORESETLOGS  ARCHIVELOG
 2      MAXLOGFILES 192
 3      MAXLOGMEMBERS 3
 4      MAXDATAFILES 1024
 5      MAXINSTANCES 32
 6      MAXLOGHISTORY 292
 7  LOGFILE
 8    GROUP 1 (
 9      '+DATA/racdb/onlinelog/group_1.261.783272805',
10      '+RECO/racdb/onlinelog/group_1.257.783272807'
11    ) SIZE 50M BLOCKSIZE 512,
12    GROUP 2 (
13      '+DATA/racdb/onlinelog/group_2.262.783272807',
14      '+RECO/racdb/onlinelog/group_2.258.783272809'
15    ) SIZE 50M BLOCKSIZE 512,
16    GROUP 3 (
17      '+DATA/racdb/onlinelog/group_3.269.804115405',
18      '+RECO/racdb/onlinelog/group_3.261.804115405'
19    ) SIZE 50M BLOCKSIZE 512,
20    GROUP 4 (
21      '+DATA/racdb/onlinelog/group_4.270.804115405',
22      '+RECO/racdb/onlinelog/group_4.263.804115407'
23    ) SIZE 50M BLOCKSIZE 512
24  -- STANDBY LOGFILE
25  DATAFILE
26    '+DATA/racdb/datafile/system.256.783272707',
27    '+DATA/racdb/datafile/sysaux.257.783272707',
28    '+DATA/racdb/datafile/undotbs1.258.783272707',
29    '+DATA/racdb/datafile/users.259.783272707',
30    '+DATA/racdb/datafile/example.264.783272831',
31    '+DATA/racdb/datafile/undotbs2.265.783273081'
32  CHARACTER SET AL32UTF8
33  ;

Control file created.

SQL> select * from v$log; <===确认redo log，thread#是正确的

   GROUP#    THREAD#  SEQUENCE#      BYTES  BLOCKSIZE    MEMBERS ARC
---------- ---------- ---------- ---------- ---------- ---------- ---
STATUS           FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------------- ------------- --------- ------------ ---------
        1          1         11   52428800        512          2 NO
CURRENT                6876599 08-JAN-13   2.8147E+14

        2          1        10   52428800        512          2 NO
INACTIVE               6825446 07-JAN-13      6876599 08-JAN-13

        3          2          7   52428800        512          2 NO
INACTIVE               6877338 08-JAN-13      6960724 08-JAN-13


   GROUP#    THREAD#  SEQUENCE#      BYTES  BLOCKSIZE    MEMBERS ARC
---------- ---------- ---------- ---------- ---------- ---------- ---
STATUS           FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------------- ------------- --------- ------------ ---------
        4          2        6   52428800        512          2 NO
INACTIVE               6815353 07-JAN-13      6877338 08-JAN-13

SQL> recover database;
ORA-00283: recovery session canceled due to errors
ORA-00264: no recovery required

SQL> alter system  archive log all;

System altered.

SQL> alter database open;

Database altered.

SQL> ALTER TABLESPACE TEMP ADD TEMPFILE '+DATA/racdb/tempfile/temp.263.783272821'
 2       SIZE 39845888  REUSE AUTOEXTEND ON NEXT 655360  MAXSIZE 32767M; 《==别忘了添加原来的临时文件到临时表空间中

Tablespace altered.

6.将cluster_database设为true :
SQL> alter system set cluster_database=true scope=spfile;

System altered.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> exit

Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options

7. 启动所有实例：
[oracle@rac1 trace]$ srvctl start database -d RACDB
[oracle@rac1 trace]$ srvctl status database -d RACDB
Instance RACDB1 is running on node rac1
Instance RACDB2 is running on node rac2

TESTCASE2
---------------------------
用resetlogs模式重建控制文件

Test Process:

1.首先生成重建控制文件的脚本：
SQL> alter database backup controlfile to trace;

Database altered.

2. 数据库的Alert log中也会详细输出这个文件的路径和名字：
alter database backup controlfile to trace
Backup controlfile written to trace file /u01/app/oracle/diag/rdbms/racdb/RACDB1/trace/RACDB1_ora_5649.trc

3. 设置cluster_database=false：
SQL> alter system set cluster_database=false scope=spfile;
System altered.

否则，在重建控制文件的时候会报下面的错误：

CREATE CONTROLFILE REUSE DATABASE "RACDB" RESETLOGS  ARCHIVELOG
*
ERROR at line 1:
ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode

4. 停止所有数据库实例：
[oracle@rac1 trace]$ srvctl stop database -d RACDB
[oracle@rac1 trace]$ srvctl status database -d RACDB
Instance RACDB1 is not running on node rac1
Instance RACDB2 is not running on node rac2

5. 用resetlogs模式重建控制文件：

[oracle@rac1 trace]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Tue Jan 8 12:45:25 2013

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount;
ORACLE instance started.

Total System Global Area  739065856 bytes
Fixed Size                  2232032 bytes
Variable Size             549454112 bytes
Database Buffers          184549376 bytes
Redo Buffers                2830336 bytes

SQL> CREATE CONTROLFILE REUSE DATABASE "RACDB" RESETLOGS  ARCHIVELOG
 2      MAXLOGFILES 192
 3      MAXLOGMEMBERS 3
 4      MAXDATAFILES 1024
 5      MAXINSTANCES 32
 6      MAXLOGHISTORY 292
 7  LOGFILE
 8    GROUP 1 (
 9      '+DATA/racdb/onlinelog/group_1.261.783272805',
10      '+RECO/racdb/onlinelog/group_1.257.783272807'
11    ) SIZE 50M BLOCKSIZE 512,
12    GROUP 2 (
13      '+DATA/racdb/onlinelog/group_2.262.783272807',
14      '+RECO/racdb/onlinelog/group_2.258.783272809'
15    ) SIZE 50M BLOCKSIZE 512
16  -- STANDBY LOGFILE
17  DATAFILE
18    '+DATA/racdb/datafile/system.256.783272707',
19    '+DATA/racdb/datafile/sysaux.257.783272707',
20    '+DATA/racdb/datafile/undotbs1.258.783272707',
21    '+DATA/racdb/datafile/users.259.783272707',
22    '+DATA/racdb/datafile/example.264.783272831',
23    '+DATA/racdb/datafile/undotbs2.265.783273081'
24  CHARACTER SET AL32UTF8
25  ;

Control file created.

SQL> RECOVER DATABASE USING BACKUP CONTROLFILE UNTIL CANCEL;  <=========必须使用UNTIL CANCEL，否则数据库无法open
ORA-00279: change 6976933 generated at 01/08/2013 12:45:12 needed for thread 1
ORA-00289: suggestion : +RECO
ORA-00280: change 6976933 for thread 1 is in sequence #2


Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
CANCEL 
Media recovery cancelled.

接下来需要��加其他thread，因为用resetlogs重建controlfile只是增加了thread为1的redo log：

SQL> ALTER DATABASE ADD LOGFILE THREAD 2
 2    GROUP 3 (
 3      '+DATA/racdb/onlinelog/group_3.269.804115405',
 4      '+RECO/racdb/onlinelog/group_3.261.804115405'
 5    ) SIZE 50M BLOCKSIZE 512 REUSE,
 6    GROUP 4 (
 7      '+DATA/racdb/onlinelog/group_4.270.804115405',
 8      '+RECO/racdb/onlinelog/group_4.263.804115407'
 9    ) SIZE 50M BLOCKSIZE 512 REUSE;
ALTER DATABASE ADD LOGFILE THREAD 2
*
ERROR at line 1:
ORA-01276: Cannot add file +DATA/racdb/onlinelog/group_3.269.804115405.  File
has an Oracle Managed Files file name. 

对于ASM，使用了OMF命名规则时不能指定具体的文件名，只需要指定diskgroup名即可：

SQL> ALTER DATABASE ADD LOGFILE THREAD 2
 2    GROUP 3 (
 3      '+DATA',
 4      '+RECO'
 5    ) SIZE 50M BLOCKSIZE 512 REUSE,
 6    GROUP 4 (
 7      '+DATA',
 8      '+RECO'
 9    ) SIZE 50M BLOCKSIZE 512 REUSE;

Database altered.

SQL> ALTER DATABASE OPEN RESETLOGS;

Database altered.

SQL> ALTER TABLESPACE TEMP ADD TEMPFILE '+DATA/racdb/tempfile/temp.263.783272821'
 2           SIZE 39845888  REUSE AUTOEXTEND ON NEXT 655360  MAXSIZE 32767M;

Tablespace altered.

6. 设置cluster_database=true :
SQL> alter system set cluster_database=true scope=spfile;

System altered.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

7. 启动所有实例：

[oracle@rac1 trace]$ srvctl start database -d RACDB
[oracle@rac1 trace]$ srvctl status database -d RACDB
Instance RACDB1 is running on node rac1
Instance RACDB2 is running on node rac2 

在My Oracle Support中有针对重建控制文件的一些说明：
How to Recreate a Controlfile (Doc ID 735106.1)