日志文件损坏恢复（实验）

目录

一，单个日志成员文件损坏（某个日志组下有多个成员文件，单个成员文件损坏）

二、数据库正常关闭，发现某一个组下面所有成员文件都损坏了。

  1、丢失的组不是CURRENT 组的所有成员文件。

  2、丢失的组是CURRENT组所成员文件

三、数据库非正常关闭，发现某一个日志组下的成员文件都损坏了（非正常关闭来不及写脏数据）

     

查看当前日志组成员：
SQL> select GROUP#,STATUS,MEMBER from v$logfile order by 1;

GROUP# STATUS  MEMBER
---------- ------- ----------------------------------------
1         /oracle/oradata/testdb/redo01c.log
1         /oracle/oradata/testdb/redo01a.log
1         /oracle/oradata/testdb/redo01b.log
2         /oracle/oradata/testdb/redo02a.log
2         /oracle/oradata/testdb/redo02c.log
2         /oracle/oradata/testdb/redo02b.log
3         /oracle/oradata/testdb/redo03c.log
3         /oracle/oradata/testdb/redo03b.log
3         /oracle/oradata/testdb/redo03d.log
3         /oracle/oradata/testdb/redo03a.log

10 rows selected.

删除一个日志成员（故障点）
[oracle@oracledb testdb]$ rm -rf redo03a.log

发现丢失日志文件以后，在v$logfile中没有立即标示出INVALID，此时重启数据库。
在丢失日志成员文件情况下，数据库能够正常重启。此时才显示出INVALID。

SQL> select GROUP#,STATUS,MEMBER from v$logfile order by 1;

GROUP# STATUS  MEMBER
---------- ------- ----------------------------------------
1         /oracle/oradata/testdb/redo01c.log
1         /oracle/oradata/testdb/redo01a.log
1         /oracle/oradata/testdb/redo01b.log
2         /oracle/oradata/testdb/redo02a.log
2         /oracle/oradata/testdb/redo02c.log
2         /oracle/oradata/testdb/redo02b.log
3         /oracle/oradata/testdb/redo03c.log
3         /oracle/oradata/testdb/redo03b.log
3         /oracle/oradata/testdb/redo03d.log
3 INVALID /oracle/oradata/testdb/redo03a.log

进行恢复:

（1）先删除数据库中对应的成员文件记录：
SQL> alter database drop logfile member '/oracle/oradata/testdb/redo03a.log';

Database altered.
（2）在重新添加新的成员日志文件：
SQL> alter database add logfile member '/oracle/oradata/testdb/redo03a.log' to group 3;

Database altered.

此时恢复完毕，可以正常使用了。

二、数据库正常关闭，发现某一个组下面所有成员文件都损坏了。

    1、 丢失的组不是CURRENT 组的所有成员文件。

查看前置环境：
SQL> select group#,status from v$log;

GROUP# STATUS
---------- ----------------
1 INACTIVE
2 CURRENT
3 INACTIVE

已知group 2 是current

正常关库：
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

删除日志group 1所有成员文件（故障点）：
[oracle@oracledb testdb]$ rm redo01*

尝试打开实例：
SQL> startup
ORA-32004: obsolete and/or deprecated parameter(s) specified
ORACLE instance started.

Total System Global Area 1058779136 bytes
Fixed Size                  1304616 bytes
Variable Size             704645080 bytes
Database Buffers          348127232 bytes
Redo Buffers                4702208 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01a.log'
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01b.log'
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01c.log'
只能打开到mount阶段，并且报错。

错误恢复：
此时数据库已经处于mount状态。
查看日志组信息，发现并非current组所有成员丢失。
SQL> select group#,status from v$log;

GROUP# STATUS
---------- ----------------
1 INACTIVE
3 INACTIVE
2 CURRENT
（1）用clear日志组的方式，清理日志组。
SQL> alter database clear logfile group 1;

Database altered.
清理的过程中，oracle实例自动重建了刚刚丢失的所有日志文件。
（2）查看，恢复的所有日志文件（被重建）
[oracle@oracledb testdb]$ ls -a |grep 'redo01'
redo01a.log
redo01b.log
redo01c.log

此时数据就能打开了：
SQL> alter database open;

Database altered.

2、丢失的组是CURRENT组所成员文件

查看前置环境：
SQL> select group#,status from v$log;

GROUP# STATUS
---------- ----------------
1 UNUSED
2 CURRENT
3 INACTIVE
发现group 2是CURRENT组

正常关闭数据库：
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

删除CURRENT组下所有成员文件：（故障点）
[oracle@oracledb testdb]$ rm -rf redo02*
[oracle@oracledb testdb]$ ls -a | grep 'redo02'

打开数据库,提示错误。

SQL> startup;
ORA-32004: obsolete and/or deprecated parameter(s) specified
ORACLE instance started.

Total System Global Area 1058779136 bytes
Fixed Size                  1304616 bytes
Variable Size             704645080 bytes
Database Buffers          348127232 bytes
Redo Buffers                4702208 bytes
Database mounted.
ORA-00313: open failed for members of log group 2 of thread 1
ORA-00312: online log 2 thread 1: '/oracle/oradata/testdb/redo02a.log'
ORA-00312: online log 2 thread 1: '/oracle/oradata/testdb/redo02b.log'
ORA-00312: online log 2 thread 1: '/oracle/oradata/testdb/redo02c.log'

查看发现丢失的Group 2 是CURRENT组
SQL> select group#,status from v$log;

GROUP# STATUS
---------- ----------------
1 UNUSED
3 INACTIVE
2 CURRENT
错误恢复：
（1）尝试，直接clear group 2（出错）。
SQL> alter database clear logfile group 2;
alter database clear logfile group 2
*
ERROR at line 1:
ORA-00350: log 2 of instance test (thread 1) needs to be archived
ORA-00312: online log 2 thread 1: '/oracle/oradata/testdb/redo02a.log'
ORA-00312: online log 2 thread 1: '/oracle/oradata/testdb/redo02b.log'
ORA-00312: online log 2 thread 1: '/oracle/oradata/testdb/redo02c.log'

（2）采用关键字UNARCHIVED（指明，不进行归档操作）的clear操作。
SQL> alter database clear unarchived logfile group 2;

Database altered.
发现所有日志文件被重建了：
[oracle@oracledb testdb]$ ls -a | grep 'redo02'
redo02a.log
redo02b.log
redo02c.log

现在可以打开数据库了。
SQL> alter database open;

Database altered.

三、数据库非正常关闭，发现某一个日志组下的成员文件都损坏了（非正常关闭来不及写脏数据）

1、丢失的是Active状态下日志组所有成员文件

制作脏数据：
SQL> select * from scott.emp where empno=7788;

EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7788 SCOTT      ANALYST         7566 19-APR-87       3000                    20

SQL> update scott.emp set sal=5000 where empno=7788;

1 row updated.

SQL> commit;

Commit complete.

SQL> select * from scott.emp where empno=7788;

EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7788 SCOTT      ANALYST         7566 19-APR-87       5000                    20

切换日志组：
SQL> select group#,status from v$log;

GROUP# STATUS
---------- ----------------
1 CURRENT
2 UNUSED
3 INACTIVE

SQL> alter system switch logfile;

System altered.

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

GROUP# STATUS
---------- ----------------
1 ACTIVE
2 CURRENT
3 INACTIVE

发现此时，Group 1是Active状态。
异常方式关闭数据库：
SQL> shutdown abort;
ORACLE instance shut down.

把日志组1 （ACTIVE）下的所有成员文件删除；（故障点）
[oracle@oracledb testdb]$ rm -rf redo01*
[oracle@oracledb testdb]$ ls -a | grep redo01
[oracle@oracledb testdb]$

启动数据库，报错。
SQL> startup
ORA-32004: obsolete and/or deprecated parameter(s) specified
ORACLE instance started.

Total System Global Area 1058779136 bytes
Fixed Size                  1304616 bytes
Variable Size             704645080 bytes
Database Buffers          348127232 bytes
Redo Buffers                4702208 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01c.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01b.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
ORA-00312: online log 1 thread 1: '/
b7a4
oracle/oradata/testdb/redo01a.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3

尝试，用clear方式清除Group 1，出错，表示需要实例恢复。（出错）
SQL> alter database clear logfile group 1
2  ;
alter database clear logfile group 1
*
ERROR at line 1:
ORA-01624: log 1 needed for crash recovery of instance test (thread 1)
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01a.log'
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01b.log'
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01c.log'

尝试，用archived 方式clear Group 1，出错，表示需要实例恢复。（出错）

SQL> alter database clear unarchived logfile group 1;

alter database clear unarchived logfile group 1
*
ERROR at line 1:
ORA-01624: log 1 needed for crash recovery of instance test (thread 1)
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01a.log'
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01b.log'
ORA-00312: online log 1 thread 1: '/oracle/oradata/testdb/redo01c.log'

故障恢复：<span style="color:#ff0000;">（修改参数文件，添加隐含参数“_allow_resetlogs_corruption=true”）</span>
（1）创建参数文件（关闭状态下可以执行）
SQL> create pfile from spfile;

File created.
（2）修改参数文件，添加隐含参数
[oracle@oracledb testdb]$ cd $ORACLE_HOME/dbs
[oracle@oracledb dbs]$ vi inittest.ora
参数文件添加一行：
_allow_resetlogs_corruption=true
（3）从参数文件强制启动到mount状态
SQL> startup mount pfile=$ORACLE_HOME/dbs/inittest.ora force;
ORA-32006: REMOTE_OS_AUTHENT initialization parameter has been deprecated
ORACLE instance started.

Total System Global Area 1058779136 bytes
Fixed Size                  1304616 bytes
Variable Size             704645080 bytes
Database Buffers          348127232 bytes
Redo Buffers                4702208 bytes
Database mounted.

查看参数_allow_resetlogs_corruption
SQL> show parameter _allow_resetlogs_corruption;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
_allow_resetlogs_corruption          boolean     TRUE

（4）用 resetlogs方式打开数据库，出错：（出错）
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01139: RESETLOGS option only valid after an incomplete database recovery

（5）假意做不完全恢复。
SQL> recover database until cancel;     --假意做不完全恢复。
ORA-00279: change 2028843 generated at 06/09/2014 18:57:18 needed for thread 1
ORA-00289: suggestion : /oracle/oradata/archive2/archive_9c5a9c8e_1_845771110_39.log
ORA-00280: change 2028843 for thread 1 is in sequence #39

Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto
ORA-00279: change 2029584 generated at 06/09/2014 19:05:28 needed for thread 1
ORA-00289: suggestion : /oracle/oradata/archive2/archive_9c5a9c8e_1_845771110_40.log
ORA-00280: change 2029584 for thread 1 is in sequence #40
ORA-00278: log file '/oracle/oradata/archive2/archive_9c5a9c8e_1_845771110_39.log' no longer needed for this recovery

ORA-00308: cannot open archived log '/oracle/oradata/archive2/archive_9c5a9c8e_1_845771110_40.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3

（6）再尝试resetlogs打开库：<span style="color:#33cc00;">（居然打开了）</span>
SQL> alter database open resetlogs;

Database altered.

如果没有打开，如下；
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00600: internal error code, arguments: [2662], [0], [354496], [0],
[354513], [4194432], [], [], [], [], [], []
Process ID: 5083
Session ID: 1 Serial number: 5

退出会话，重新用pfile 来启动数据库

SQL> startup pfile=$ORACLE_HOME/dbs/inittest.ora;
ORACLE instance started.

Total System Global Area 1071333376 bytes
Fixed Size                  1341312 bytes
Variable Size             620759168 bytes
Database Buffers          444596224 bytes
Redo Buffers                4636672 bytes
Database mounted.
Database opened.

（7）日志组序列重置了。
SQL> select sequence#,group#,status from v$log;

SEQUENCE#     GROUP# STATUS
---------- ---------- ----------------
1          1 CURRENT
0          2 UNUSED
0          3 UNUSED

检查脏数据是否有丢失，居然没有丢失

SQL> select * from scott.emp where empno=7788;

EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7788 SCOTT      ANALYST         7566 19-APR-87       5000                    20

并且重建了已经丢失的Group1

SQL> select * from v$logfile order by 1;

GROUP# STATUS  TYPE    MEMBER                                   IS_
---------- ------- ------- ---------------------------------------- ---
1         ONLINE  /oracle/oradata/testdb/redo01c.log       NO
1         ONLINE  /oracle/oradata/testdb/redo01a.log       NO
1         ONLINE  /oracle/oradata/testdb/redo01b.log       NO
2         ONLINE  /oracle/oradata/testdb/redo02a.log       NO
2         ONLINE  /oracle/oradata/testdb/redo02c.log       NO
2         ONLINE  /oracle/oradata/testdb/redo02b.log       NO
3         ONLINE  /oracle/oradata/testdb/redo03d.log       NO
3         ONLINE  /oracle/oradata/testdb/redo03c.log       NO
3         ONLINE  /oracle/oradata/testdb/redo03a.log       NO
3         ONLINE  /oracle/oradata/testdb/redo03b.log       NO

10 rows selected.

注意：resetlogs 打开数据库，以及unarchived 清除日志组后需要立即重新备份数据库。