控制文件恢复实验系列（1）

[3.1]镜像恢复
     背景：控制文件有镜像，数据库在运行时某个控制文件突然损坏
1：查询当前数据库控制文件：

2：移动控制文件

3：启动数据库报错

4：使用镜像副本cp

sys@ORCL> !cp /u01/app/oracle/oradata/orcl/control02.ctl /u01/app/oracle/oradata/orcl/control01.ctl

5：启动数据库

sys@ORCL> alter database mount;
sys@ORCL> alter database open;  

[3.2]控制文件损坏，有二进制备份，异常关闭
1：创建一个二进制控制文件

sys@ORCL> alter database backup controlfile to '/backup/ctl.ctl' reuse;
Database altered.
2：创建一个实验表

sys@ORCL> create table t1 (x int);
Table created.
sys@ORCL> insert into t1 values(1);
1 row created.

sys@ORCL> commit;
Commit complete.
3：模拟数据文件损坏并异常关闭数据库

[root@Lee orcl]# mv control0* /home
sys@ORCL> shutdown abort;
ORACLE instance shut down.

4：启动数据库，报ORA-00205错误

5：使用二进制文件恢复控制文件

sys@ORCL> !cp /home/control01.ctl /u01/app/oracle/oradata/orcl/control01.ctl
sys@ORCL> !cp /home/control02.ctl /u01/app/oracle/oradata/orcl/control02.ctl
sys@ORCL> !cp /home/control03.ctl /u01/app/oracle/oradata/orcl/control03.ctl
sys@ORCL> startup force mount;
ORACLE instance started.
Total System Global Area  784998400 bytes
Fixed Size                  2257352 bytes
Variable Size             499125816 bytes
Database Buffers          281018368 bytes
Redo Buffers                2596864 bytes
Database mounted.
6：查看数据文件检查点SCN

从上图可以看出控制文件最后SCN与开始SCN 不一致，数据库需要前滚到 402831521，前滚的开始SCN是： 402831071

所以我们使用

sys@ORCL> alter database open;
alter database open
*

ERROR at line 1:
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open

6：恢复数据库

7：最终打开数据库：

sys@ORCL> alter database open resetlogs;
Database altered

[3.3]控制文件损坏，有二进制备份，正常关闭数据库
     背景:控制文件全部丢失，有二进制备份，数据库是正常关闭的
1：备份控制文件的二进制文件：

sys@ORCL> alter database backup controlfile to '/backup/ctl.ctl' reuse;
Database altered.

2：创建测试表、正常关闭数据库：

sys@ORCL> drop table t1;
Table dropped.

sys@ORCL> create table t1(x int);
Table created.

sys@ORCL> insert into t1 values (1);
1 row created.

sys@ORCL> commit;
Commit complete.

sys@ORCL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

3：删除数据库的控制文件

[root@Lee orcl]# mv control0* /home/

4：启动数据库报错

sys@ORCL> startup;
ORACLE instance started.

Total System Global Area  784998400 bytes
Fixed Size                  2257352 bytes
Variable Size             499125816 bytes
Database Buffers          281018368 bytes
Redo Buffers                2596864 bytes
ORA-00205: error in identifying control file, check alert log for more info

5：使用二进制文件恢复控制你文件

sys@ORCL> !cp /backup/ctl.ctl /u01/app/oracle/oradata/orcl/control01.ctl

sys@ORCL> !cp /backup/ctl.ctl /u01/app/oracle/oradata/orcl/control02.ctl

sys@ORCL> !cp /backup/ctl.ctl /u01/app/oracle/oradata/orcl/control03.ctl

6：尝试mount数据库

sys@ORCL> alter database moount;
alter database moount
                    *
ERROR at line 1:
ORA-02231: missing or invalid option to ALTER DATABASE

上面报错，主要原因如下：

开始SCN>检查点SCN，数据库需要前滚，前滚的起点为老的控制文件号：

8：执行前滚

9：打开数据库

sys@ORCL> alter database open resetlogs;
Database altered.

sys@ORCL> select * from t1;
         X
----------
         1

[3.4]有trace的备份，正常关机
     背景:控制文件丢失,有TRACE备份
1：生成控制文件备份文件

sys@ORCL> alter database backup controlfile to trace as '/backup/ctl.sql' reuse;

Database altered.
2：创建测试表

sys@ORCL> truncate table t1;

Table truncated.

sys@ORCL> insert into t1 values(1);

1 row created.

sys@ORCL> commit;

Commit complete.
3：正常关闭数据库、移动控制文件

sys@ORCL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

[root@Lee orcl]# mv control0* /home

4：启动数据库报错

sys@ORCL> startup;
ORACLE instance started.
Total System Global Area  784998400 bytes
Fixed Size                  2257352 bytes
Variable Size             499125816 bytes
Database Buffers          281018368 bytes
Redo Buffers                2596864 bytes
ORA-00205: error in identifying control file, check alert log for more info

5：使用trace文件新建数据库

sys@ORCL> CREATE CONTROLFILE REUSE DATABASE "ORCL"  NORESETLOGS  ARCHIVELOG
  2      MAXLOGFILES 16
  3      MAXLOGMEMBERS 3
  4      MAXDATAFILES 100
  5      MAXINSTANCES 8
  6      MAXLOGHISTORY 4674
  7  LOGFILE
  8    GROUP 1 '/u01/app/oracle/oradata/orcl/redo01.log'  SIZE 50M BLOCKSIZE 512,
  9    GROUP 2 '/u01/app/oracle/oradata/orcl/redo02.log'  SIZE 50M BLOCKSIZE 512,
10    GROUP 3 '/u01/app/oracle/oradata/orcl/redo03.log'  SIZE 50M BLOCKSIZE 512
11  -- STANDBY LOGFILE
12  DATAFILE
13    '/u01/app/oracle/oradata/orcl/system01.dbf',
14    '/u01/app/oracle/oradata/orcl/sysaux01.dbf',
15    '/u01/app/oracle/oradata/orcl/undotbs01.dbf',
16    '/u01/app/oracle/oradata/orcl/users01.dbf',
17    '/u01/app/oracle/oradata/orcl/example01.dbf',
18    '/u01/app/oracle/oradata/orcl/users02.dbf'
19  CHARACTER SET ZHS16GBK;

Control file created.
此处选择 NORESETLOGS创建的控制文件，则此时将控制文件、数据文件、日志文件作为当前状态，他会读取当前控制文件指定的物理结构的文件上读取文件头，来构建控制文件

开始SCN跟结束SCN和datafile checkpoint SCN 都相等，都是当前

6：直接打开数据库

sys@ORCL> alter database open;
Database altered.

sys@ORCL> select * from t1;
         X
----------
         1

[3.5]有trace noresetlogs的备份，异常关机
1：生成trace备份

sys@ORCL> alter database backup controlfile to trace as '/backup/ctl.sql' reuse noresetlogs;
Database altered.

2：创建测试表并切换归档

sys@ORCL> truncate table t1;
Table truncated.

sys@ORCL> insert into t1 values(1);
1 row created.

sys@ORCL> commit ;
Commit complete.

sys@ORCL> alter system switch logfile;
System altered.

sys@ORCL> /
System altered.

3：异常关闭数据库，并启动数据库报错

sys@ORCL> shutdown abort;
ORACLE instance shut down.

sys@ORCL> startup;
ORACLE instance started.
Total System Global Area  784998400 bytes
Fixed Size                  2257352 bytes
Variable Size             499125816 bytes
Database Buffers          281018368 bytes
Redo Buffers                2596864 bytes
ORA-00205: error in identifying control file, check alert log for more info

4：使用trace备份生成控制文件

CREATE CONTROLFILE REUSE DATABASE "ORCL" NORESETLOGS  ARCHIVELOG
  2      MAXLOGFILES 16
  3      MAXLOGMEMBERS 3
  4      MAXDATAFILES 100
  5      MAXINSTANCES 8
  6      MAXLOGHISTORY 4674
  7  LOGFILE
  8    GROUP 1 '/u01/app/oracle/oradata/orcl/redo01.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 2 '/u01/app/oracle/oradata/orcl/redo02.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 3 '/u01/app/oracle/oradata/orcl/redo03.log'  SIZE 50M BLOCKSIZE 512
11  -- STANDBY LOGFILE
12  DATAFILE
13    '/u01/app/oracle/oradata/orcl/system01.dbf',
14    '/u01/app/oracle/oradata/orcl/sysaux01.dbf',
15    '/u01/app/oracle/oradata/orcl/undotbs01.dbf',
16    '/u01/app/oracle/oradata/orcl/users01.dbf',
17    '/u01/app/oracle/oradata/orcl/example01.dbf',
18    '/u01/app/oracle/oradata/orcl/users02.dbf'
19  CHARACTER SET ZHS16GBK;
Control file created.

5：查看数据文件头

6：恢复数据库，并打开数据库

sys@ORCL> recover database;
Media recovery complete.

sys@ORCL> alter database open;
Database altered.

sys@ORCL> select * from t1;
         X
----------
         1

[3.6]trace 控制文件RESETLOGS方式创建，非活动在线日志损坏，并异常关闭
     背景:控制文件全部丢失，但是有TRACE文件，非活动的在线日志损坏，异常关机
1：生成trace文件

sys@ORCL> alter database backup controlfile to trace as '/backup/ctl.sql' reuse;
Database altered.

2：查询当前使用的日志组，删除未活动日志和控制文件

[root@Lee orcl]# mv control0* /home/
[root@Lee orcl]# mv redo01.log /home/
[root@Lee orcl]# mv redo03.log /home/

3：异常关闭数据库并启动数据库报错

sys@ORCL> shutdown abort;
ORACLE instance shut down.

sys@ORCL> startup;
ORACLE instance started.
Total System Global Area  784998400 bytes
Fixed Size                  2257352 bytes
Variable Size             499125816 bytes
Database Buffers          281018368 bytes
Redo Buffers                2596864 bytes
ORA-00205: error in identifying control file, check alert log for more info

4：创建控制文件

sys@ORCL> CREATE CONTROLFILE REUSE DATABASE "ORCL"  NORESETLOGS  ARCHIVELOG
  2      MAXLOGFILES 16
  3      MAXLOGMEMBERS 3
  4      MAXDATAFILES 100
  5      MAXINSTANCES 8
  6      MAXLOGHISTORY 4674
  7  LOGFILE
  8    GROUP 1 '/u01/app/oracle/oradata/orcl/redo01.log'  SIZE 50M BLOCKSIZE 512,
  9    GROUP 2 '/u01/app/oracle/oradata/orcl/redo02.log'  SIZE 50M BLOCKSIZE 512,
10    GROUP 3 '/u01/app/oracle/oradata/orcl/redo03.log'  SIZE 50M BLOCKSIZE 512
11  -- STANDBY LOGFILE
12  DATAFILE
13    '/u01/app/oracle/oradata/orcl/system01.dbf',
14    '/u01/app/oracle/oradata/orcl/sysaux01.dbf',
15    '/u01/app/oracle/oradata/orcl/undotbs01.dbf',
16    '/u01/app/oracle/oradata/orcl/users01.dbf',
17    '/u01/app/oracle/oradata/orcl/example01.dbf',
18    '/u01/app/oracle/oradata/orcl/users02.dbf'
19  CHARACTER SET ZHS16GBK;
ERROR:
ORA-06550: line 1, column 29:
PLS-00553: character set name is not recognized
ORA-06550: line 0, column 0:
PL/SQL: Compilation unit analysis terminated

此处我们使用 NORESETLOGS创建数据库报错，原因是NORESETLOGS来创建控制文件时会读取在线日志头，所以使用resetlogs来创建

CREATE CONTROLFILE REUSE DATABASE "ORCL" RESETLOGS  ARCHIVELOG
  2      MAXLOGFILES 16
  3      MAXLOGMEMBERS 3
  4      MAXDATAFILES 100
  5      MAXINSTANCES 8
  6      MAXLOGHISTORY 4674
  7  LOGFILE
  8    GROUP 1 '/u01/app/oracle/oradata/orcl/redo01.log'  SIZE 50M BLOCKSIZE 512,
  9    GROUP 2 '/u01/app/oracle/oradata/orcl/redo02.log'  SIZE 50M BLOCKSIZE 512,
10    GROUP 3 '/u01/app/oracle/oradata/orcl/redo03.log'  SIZE 50M BLOCKSIZE 512
11  -- STANDBY LOGFILE
12  DATAFILE
13    '/u01/app/oracle/oradata/orcl/system01.dbf',
14    '/u01/app/oracle/oradata/orcl/sysaux01.dbf',
15    '/u01/app/oracle/oradata/orcl/undotbs01.dbf',
16    '/u01/app/oracle/oradata/orcl/users01.dbf',
17    '/u01/app/oracle/oradata/orcl/example01.dbf',
18    '/u01/app/oracle/oradata/orcl/users02.dbf'
19  CHARACTER SET ZHS16GBK
20  ;
Control file created.

5：此时我们尝试打开数据库
sys@ORCL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/u01/app/oracle/oradata/orcl/system01.dbf'

提示需要进行数据库恢复

打开数据库

sys@ORCL> alter database open resetlogs;
Database altered.

sys@ORCL> select * from t1;
         X
----------
         1