作者：炎燚小寳

原文链接：【Oracle OCP】oracle 19c 之控制文件管理 - 课程体系 - 云贝教育

一、什么是控制文件

每个Oracle数据库都有一个控制文件，它是一个小的二进制文件，记录了数据库的物理结构。

The database name-->数据库名称
Names and locations of associated data files and redo log files -->数据文件和日志文件的路径 
The timestamp of the database creation -->数据库创建的时间
The current log sequence number -->当前日志的序列号
Checkpoint information -->数据库检查点信息

二、配置控制文件多路复用

Oracle数据库的控制文件是与数据库同时创建的。默认情况下，在创建数据库期间至少创建控制文件的一个副本。在某些操作系统上，默认是创建多个副本。在创建数据库期间，应该创建控制文件的两个或多个副本。如果丢失了控制文件或希望更改控制文件中的特定设置，也可以稍后创建控制文件。

2.1 查看当前数据库的控制文件(pdb和cdb共享)

SYS@ORCLCDB> show parameter control_files
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
control_files                        string      /opt/oracle/oradata/ORCLCDB/co
                                                 ntrol01.ctl, /opt/oracle/orada
                                                 ta/ORCLCDB/control02.ctl
SYS@ORCLCDB> select name from v$controlfile;
NAME
--------------------------------------------------------------------------------
/opt/oracle/oradata/ORCLCDB/control01.ctl
/opt/oracle/oradata/ORCLCDB/control02.ctl

2.2 修改控制文件多路复用

1、修改参数
SYS@ORCLCDB>alter system set control_files='/opt/oracle/oradata/ORCLCDB/control01.ctl', '/opt/oracle/oradata/ORCLCDB/control02.ctl','/opt/oracle/oradata/ORCLCDB/control03.ctl' scope=spfile;
2、关闭数据库
SYS@ORCLCDB> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
3、操作系统上CP控制文件
[oracle@database ORCLCDB]$ cp control01.ctl control03.ctl
4、启动数据库
SYS@ORCLCDB> startup;

提问：如果失误将控制文件参数改成如下格式，如何通过修改参数文件将数据库OPEN

1、修改控制文件参数
alter system set control_files='/opt/oracle/oradata/ORCLCDB/control01.ctl', '/opt/oracle/oradata/ORCLCDB/control02.ctl','/opt/oracle/oradata/ORCLCDB/control03ctl' scope=spfile;
               
2、而实际3号控制文件是这样的
[oracle@database ORCLCDB]$ ll
total 2715912
-rw-r----- 1 oracle oinstall  18726912 Jul  6 02:32 control01.ctl
-rw-r----- 1 oracle oinstall  18726912 Jul  6 02:32 control02.ctl
-rw-r----- 1 oracle oinstall  18726912 Jul  6 02:34 control03.ctl-->参数文件里是control03ctl

三、控制文件的备份与重建

3.1 通过 TRACE 备份

意义上来说，不是针对控制文件的备份，而是根据现在系统情况生成了一份 trace文件，这个 trace 文件中记录了创建控制文件的基本信息。

1、CDB下执行，PDB无法执行
SQL> alter database backup controlfile to trace;

上面这句话生成的 trace 文件在 dump 里面，可以通过告警日志查看。

2023-07-06T07:23:56.772531-07:00
alter database backup controlfile to trace
2023-07-06T07:23:56.856692-07:00
Backup controlfile written to trace file /opt/oracle/diag/rdbms/orclcdb/ORCLCDB/trace/ORCLCDB_ora_16999.trc
Completed: alter database backup controlfile to trace

具体内容见附件

CREATE CONTROLFILE REUSE DATABASE "ORCLCDB" NORESETLOGS  NOARCHIVELOG
    MAXLOGFILES 16
    MAXLOGMEMBERS 3
    MAXDATAFILES 1024
    MAXINSTANCES 8
    MAXLOGHISTORY 292
LOGFILE
  GROUP 1 '/opt/oracle/oradata/ORCLCDB/redo01.log'  SIZE 200M BLOCKSIZE 512,
  GROUP 2 '/opt/oracle/oradata/ORCLCDB/redo02.log'  SIZE 200M BLOCKSIZE 512,
  GROUP 3 '/opt/oracle/oradata/ORCLCDB/redo03.log'  SIZE 200M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
  '/opt/oracle/oradata/ORCLCDB/system01.dbf',
  '/opt/oracle/oradata/ORCLCDB/sysaux01.dbf',
  '/opt/oracle/oradata/ORCLCDB/undotbs01.dbf',
  '/opt/oracle/oradata/ORCLCDB/pdbseed/system01.dbf',
  '/opt/oracle/oradata/ORCLCDB/pdbseed/sysaux01.dbf',
  '/opt/oracle/oradata/ORCLCDB/users01.dbf',
  '/opt/oracle/oradata/ORCLCDB/pdbseed/undotbs01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/system01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/sysaux01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/undotbs01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/users01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/tbs_t201.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/tbs_big01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_d_l9qy2qvq_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_data_l9qz094v_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_idx_l9qz0jbq_.dbf',
  '/opt/oracle/product/19c/dbhome_1/dbs/shadow_lwp1_df',
  '/opt/oracle/oradata/ORCLCDB/test1.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_16k_l9thkbf9_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs1_l9y26m6z_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs2_l9y3f1bt_.dbf'
CHARACTER SET AL32UTF8
;

3.2 通过 BINARY 二进制备份

这种方式是针对控制文件的热备份。

--CDB下执行

SYS@ORCLCDB> alter database backup controlfile to '/home/oracle/ctl.bak';

Database altered.

四、控制文件丢失/损坏恢复

4.1 丢失/损坏多个控制文件中的一个

模拟单个控制文件损坏，删除其中一个控制文件。数据库无法启动。

方案有两种：1、直接复制多路复用中的其他控制文件 2、通过pfile修改控制文件的参数，将损坏的控制文件删掉

1）、通过OS层复制参数文件

1、关闭数据库
SYS@ORCLCDB> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.


2、删除其中一个控制文件
[oracle@database ORCLCDB]$ rm control03.ctl 


3、启动数据库失败
SYS@ORCLCDB> startup
ORACLE instance started.
Total System Global Area  759166168 bytes
Fixed Size                  9139416 bytes
Variable Size             583008256 bytes
Database Buffers           58720256 bytes
Redo Buffers                3440640 bytes
In-Memory Area            104857600 bytes
ORA-00205: error in identifying control file, check alert log for more info


4、具体报错如下，提示3号文件未找到
ALTER DATABASE   MOUNT
2023-07-06T08:05:16.072594-07:00
ORA-00210: cannot open the specified control file
ORA-00202: control file: '/opt/oracle/oradata/ORCLCDB/control03ctl'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 7
ORA-205 signalled during: ALTER DATABASE   MOUNT...
2023-07-06T08:05:16.144178-07:00
Errors in file /opt/oracle/diag/rdbms/orclcdb/ORCLCDB/trace/ORCLCDB_mz00_17712.trc:
ORA-00202: control file: '/opt/oracle/oradata/ORCLCDB/control03ctl'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 7


5、复制一个控制文件
[oracle@database ORCLCDB]$ cp control01.ctl control03.ctl


6、再次启动数据库成功

2）、通过pfile修改控制文件

1、关闭数据库
SYS@ORCLCDB> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.


2、删除其中一个控制文件
[oracle@database ORCLCDB]$ rm control03.ctl 


3、启动数据库失败
SYS@ORCLCDB> startup
ORACLE instance started.
Total System Global Area  759166168 bytes
Fixed Size                  9139416 bytes
Variable Size             583008256 bytes
Database Buffers           58720256 bytes
Redo Buffers                3440640 bytes
In-Memory Area            104857600 bytes
ORA-00205: error in identifying control file, check alert log for more info


4、创建pfile，修改参数文件
SYS@ORCLCDB> create pfile from spfile;
File created
[oracle@database dbs]$cd /opt/oracle/product/19c/dbhome_1/dbs
--修改参数文件vi initORCLCDB.ora 
将损坏的参数文件删除
*.control_files='/opt/oracle/oradata/ORCLCDB/control01.ctl','/opt/oracle/oradata/ORCLCDB/control02.ctl'
5、以pfile启动数据库
startup pfile='/opt/oracle/product/19c/dbhome_1/dbs/initORCLCDB.ora'

4.2 所有控制文件损坏

参照控制文件，我们需要找到以下信息

1、日志文件名称，体积和块大小


2、所有的dbf文件


3、数据库的名称和字符集
CREATE CONTROLFILE REUSE DATABASE "ORCLCDB" NORESETLOGS  NOARCHIVELOG
    MAXLOGFILES 16
    MAXLOGMEMBERS 3
    MAXDATAFILES 1024
    MAXINSTANCES 8
    MAXLOGHISTORY 292
LOGFILE
  GROUP 1 '/opt/oracle/oradata/ORCLCDB/redo01.log'  SIZE 200M BLOCKSIZE 512,
  GROUP 2 '/opt/oracle/oradata/ORCLCDB/redo02.log'  SIZE 200M BLOCKSIZE 512,
  GROUP 3 '/opt/oracle/oradata/ORCLCDB/redo03.log'  SIZE 200M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
  '/opt/oracle/oradata/ORCLCDB/system01.dbf',
  '/opt/oracle/oradata/ORCLCDB/sysaux01.dbf',
  '/opt/oracle/oradata/ORCLCDB/undotbs01.dbf',
  '/opt/oracle/oradata/ORCLCDB/pdbseed/system01.dbf',
  '/opt/oracle/oradata/ORCLCDB/pdbseed/sysaux01.dbf',
  '/opt/oracle/oradata/ORCLCDB/users01.dbf',
  '/opt/oracle/oradata/ORCLCDB/pdbseed/undotbs01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/system01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/sysaux01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/undotbs01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/users01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/tbs_t201.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/tbs_big01.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_d_l9qy2qvq_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_data_l9qz094v_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_idx_l9qz0jbq_.dbf',
  '/opt/oracle/product/19c/dbhome_1/dbs/shadow_lwp1_df',
  '/opt/oracle/oradata/ORCLCDB/test1.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs_16k_l9thkbf9_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs1_l9y26m6z_.dbf',
  '/opt/oracle/oradata/ORCLCDB/ORCLPDB1/ORCLCDB/FE8CF63D04B91F62E053814AA8C03B8A/datafile/o1_mf_tbs2_l9y3f1bt_.dbf'
CHARACTER SET AL32UTF8
;