误删重做日志文件组导致启动数据库报错ORA-03113

听不止一个人说起，学技术就要不断地折腾、搞破坏，比如说备份恢复，你就可以尝试删文件，不管是日志文件、临时文件、数据文件还

听不止一个人说起，学技术就要不断地折腾、搞破坏，比如说备份恢复，你就可以尝试删文件，不管是日志文件、临时文件、数据文件还是system文件。删了之后，重启数据库肯定报错，有的甚至当时数据库就挂掉，这样你就可以学着恢复，一破一立之间，很多常规的备份恢复手段也就算是领教了。我今天就尝试着把虚拟机上的一个重做日志文件组删除。

1.环境准备

我们在Oracle11g中进行测试，数据库处于非归档状态。

SQL>

SQL> select * from v$version;

BANNER

--------------------------------------------------------------------------------

Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production

PL/SQL Release 11.2.0.3.0 - Production

CORE 11.2.0.3.0 Production

TNS for Linux: Version 11.2.0.3.0 - Production

NLSRTL Version 11.2.0.3.0 - Production

SQL>

SQL> archive log list;

Database log mode No Archive Mode

Automatic archival Disabled

Archive destination /u01/app/oracle/product/11.2.0/dbhome_1/dbs/arch

Oldest online log sequence 9

Current log sequence 11

SQL>

2.删除一个重做日志文件组，重启数据库报错

首先，通过查询v$log视图来获取数据库重做日志文件组的状态。

SQL> select GROUP#,MEMBERS,ARCHIVED,STATUS from v$log;

GROUP# MEMBERS ARC STATUS

---------- ---------- --- ----------------

1 1 NO INACTIVE

2 1 NO CURRENT

3 1 NO INACTIVE

SQL>
然后，通过ls命令查看数据文件，，删除第一个重做日志文件组（该文件组只有一个日志成员）。

[oracle@ hoegh HOEGH]$ ls

control01.ctl redo01.log sysaux01.dbf undotbs01.dbf

control02.ctl redo02.log system01.dbf users01.dbf

example01.dbf redo03.log temp01.dbf

[oracle@hoegh HOEGH]$

[oracle@hoegh HOEGH]$

[oracle@hoegh HOEGH]$ rm redo01.log

[oracle@hoegh HOEGH]$ ls

control01.ctl control02.ctl example01.dbf redo02.log redo03.log sysaux01.dbf system01.dbf temp01.dbf undotbs01.dbf users01.dbf
重启数据库，数据库报错。

SQL>

SQL> shu immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

Total System Global Area 941600768 bytes

Fixed Size 1348860 bytes

Variable Size 515902212 bytes

Database Buffers 419430400 bytes

Redo Buffers 4919296 bytes

Database mounted.

ORA-03113: end-of-file on communication channel

Process ID: 5196

Session ID: 125 Serial number: 5

SQL>

SQL> select status from v$instance;

ERROR:

ORA-03114: not connected to ORACLE

SQL>

3.查看报警日志文件，定位问题

ORA-03113报错是一个非常经典的报错，报错原因多种多样，从报错信息中并看不出是什么原因导致的报错，我们可以到报警日志文件中查看有价值的线索。

[oracle@enmoedu1 trace]$ tail -40 alert_HOEGH.log

Wed Jul 08 21:59:30 2015

MMON started with pid=15, OS id=5443

Wed Jul 08 21:59:30 2015

MMNL started with pid=16, OS id=5445

starting up 1 dispatcher(s) for network address \'(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))\'...

starting up 1 shared server(s) ...

ORACLE_BASE from environment = /u01/app/oracle

Wed Jul 08 21:59:39 2015

alter database mount

Wed Jul 08 21:59:43 2015

Successful mount of redo thread 1, with mount id 2105928075

Database mounted in Exclusive Mode

Lost write protection disabled

Completed: alter database mount

Wed Jul 08 22:11:45 2015

Time drift detected. Please check VKTM trace file for more details.

Wed Jul 08 22:11:59 2015

alter database open

Wed Jul 08 22:11:59 2015

Errors in file /u01/app/oracle/diag/rdbms/HOEGH/HOEGH/trace/HOEGH_lgwr_5435.trc:

ORA-00313: open failed for members of log group 1 of thread 1

ORA-00312: online log 1 thread 1: \'/u01/app/oracle/oradata/HOEGH/redo01.log\'

ORA-27037: unable to obtain file status

Linux Error: 2: No such file or directory

Additional information: 3

Errors in file /u01/app/oracle/diag/rdbms/HOEGH/HOEGH/trace/HOEGH_lgwr_5435.trc:

ORA-00313: open failed for members of log group 1 of thread 1

ORA-00312: online log 1 thread 1: \'/u01/app/oracle/oradata/HOEGH/redo01.log\'

ORA-27037: unable to obtain file status

Linux Error: 2: No such file or directory

Additional information: 3

Errors in file /u01/app/oracle/diag/rdbms/HOEGH/HOEGH/trace/HOEGH_ora_5451.trc:

ORA-00313: open failed for members of log group 1 of thread

ORA-00312: online log 1 thread 1: \'/u01/app/oracle/oradata/HOEGH/redo01.log\'

USER (ospid: 5451): terminating the instance due to error 313

Wed Jul 08 22:12:00 2015

System state dump requested by (instance=1, osid=5451), summary=[abnormal instance termination].

System State dumped to trace file /u01/app/oracle/diag/rdbms/HOEGH/HOEGH/trace/HOEGH_diag_5425.trc

Dumping diagnostic data in directory=[cdmp_20150708221200], requested by (instance=1, osid=5451), summary=[abnormal instance termination].

Instance terminated by USER, pid = 5451
其中，黄色标注部分为关键信息，我们知道“/u01/app/oracle/oradata/HOEGH/redo01.log”这个文件找不到了。

4.启动数据库到mount状态，重建重做日志文件组

从报警日志可以看出，第一组重做日志文件组丢了，我们可以通过sql语句“alter database clear logfile group 1;”重建日志文件组；确认日志文件创建成功后，将数据库切换到open状态。

SQL> startup nomount

ORACLE instance started.

Total System Global Area 941600768 bytes

Fixed Size 1348860 bytes

Variable Size 515902212 bytes

Database Buffers 419430400 bytes

Redo Buffers 4919296 bytes

SQL> alter database mount;

Database altered.

SQL> select group#,sequence#,archived,status from v$log;

GROUP# SEQUENCE# ARC STATUS

---------- ---------- --- ----------------

1 7 NO INACTIVE

3 6 NO INACTIVE

2 8 NO CURRENT

SQL>

SQL>

SQL>

SQL>

SQL> alter database clear logfile group 1;

Database altered.

SQL> select group#,sequence#,archived,status from v$log;

GROUP# SEQUENCE# ARC STATUS

---------- ---------- --- ----------------

1 0 NO UNUSED

3 6 NO INACTIVE

2 8 NO CURRENT

启动数据库到open状态

SQL>

SQL> alter database open;

Database altered.

SQL>

SQL> select group#,sequence#,archived,status from v$log;

GROUP# SEQUENCE# ARC STATUS

---------- ---------- --- ----------------

1 0 NO UNUSED

2 8 NO CURRENT

3 6 NO INACTIVE
此时我们再次查看文件列表，结果如下。

[oracle@hoegh HOEGH]$ ls

control01.ctl control02.ctl example01.dbf redo01.log redo02.log redo03.log sysaux01.dbf system01.dbf temp01.dbf undotbs01.dbf users01.dbf

[oracle@hoegh HOEGH]$

5.手动切换重做日志文件组
为了确保新建的日志文件组可用，我们可以手动切换日志文件组，改变新建日志文件组的状态（由UNUSED改为其他）。

SQL>

SQL> alter system switch logfile;

System altered.

SQL> select group#,sequence#,archived,status from v$log;

GROUP# SEQUENCE# ARC STATUS

---------- ---------- --- ----------------

1 9 NO CURRENT

2 8 NO ACTIVE

3 6 NO INACTIVE

SQL> alter system switch logfile;

System altered.

SQL> select group#,sequence#,archived,status from v$log;

GROUP# SEQUENCE# ARC STATUS

---------- ---------- --- ----------------

1 9 NO ACTIVE

2 8 NO ACTIVE

3 10 NO CURRENT

SQL> alter system switch logfile;

System altered.

SQL> select group#,sequence#,archived,status from v$log;

GROUP# SEQUENCE# ARC STATUS

---------- ---------- --- ----------------

1 9 NO INACTIVE

2 11 NO CURRENT

3 10 NO INACTIVE

SQL>
其中，
current:表示该日志组为当前日志组,oracle正在使用该日志组;

active:当current redo组发生日志切换时,状态会改变为active,在这个状态下,如果数据库为归档模式,archive进程会归档active日志组;如果发生数据库crash,该日志组也是实例恢复必需的日志组;

inactive:当active日志组归档完毕并且oracle判断不需要进行实例恢复时,会将其状态修改为inactive,等待下一轮的使用;所以当日志组为inactive的时候,如果数据库为归档模式.那么日志肯定是归档完成了。