Redo Log File（inactive、active）损坏，处理恢复对策

redolog的生命周期中共有四种状态：

current -> 正在使用的

active -> 非正在使用的，对应的Dirty Block还没有完全写入到数据文件中

inactive -> 非正在使用的，可以覆盖的，Dirty Block已经完全写入。

unused -> 没有使用过的

-- 查看redolog状态

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

模拟三种状态下redolog丢失，处理方案：

一、inactive 情况 （Inactive表示Dirty Block已经完全写入。）

-- 查看redolog状态

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

GROUP# STATUS

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

1 INACTIVE

2 CURRENT

3 UNUSED

SQL> 

col member for a45;

select group#,status,type,member from v$logfile;

GROUP# STATUS TYPE MEMBER

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

3 ONLINE /home/oracle/app/oradata/orcl/redo03.log

2 ONLINE /home/oracle/app/oradata/orcl/redo02.log

1 ONLINE /home/oracle/app/oradata/orcl/redo01.log

--模拟 inactive 状态丢失

[oracle@11g orcl]$ rm -rf /home/oracle/app/oradata/orcl/redo01.log

-- inactive 丢失后的数据库症状

[oracle@11g trace]$ tail -f alert_orcl.log 

Errors in file /home/oracle/app/diag/rdbms/orcl/orcl/trace/orcl_m000_25727.trc:

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

ORA-00312: online log 1 thread 1: '/home/oracle/app/oradata/orcl/redo01.log'

ORA-27037: unable to obtain file status

Linux-x86_64 Error: 2: No such file or directory

Additional information: 3

SQL> alter system switch logfile; （多切几次日志后，会话hang住）

SQL> conn andy/andy （用户登录不进去）

ERROR:

ORA-00257: archiver error. Connect internal only, until freed.

Warning: You are no longer connected to ORACLE.

--处理流程

SQL> alter database clear logfile group 1 ;

alter database clear logfile group 1

*

ERROR at line 1:

ORA-00350: log 1 of instance orcl (thread 1) needs to be archived

ORA-00312: online log 1 thread 1: '/home/oracle/app/oradata/orcl/redo01.log'

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

GROUP# SEQUENCE# ARC STATUS

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

1 4 NO INACTIVE

2 5 NO INACTIVE

3 6 NO CURRENT

SQL> alter database clear unarchived logfile group 1;

Database altered.

-- 检查redo自否正常创建

[oracle@11g ~]$ cd /home/oracle/app/oradata/orcl/

[oracle@11g orcl]$ ll redo*

-rw-r-----. 1 oracle oinstall 52429312 Mar 25 13:44 redo01.log

-rw-r-----. 1 oracle oinstall 52429312 Mar 25 13:19 redo02.log

-rw-r-----. 1 oracle oinstall 52429312 Mar 25 13:36 redo03.log

SQL> alter system switch logfile;

System altered.

SQL> /

SQL> /

SQL> /

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

GROUP# SEQUENCE# ARC STATUS

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

1 10 YES INACTIVE

2 11 YES INACTIVE

3 12 NO CURRENT

数据库恢复正常，OK。

————————————————————————————————————————————————————————

二、 active 情况 （Active是说日志组已经不是当前日志组，但是Redo Log Entry对应的Dirty Block还没有完全写入到数据文件中。）

--切换日志直至 redolog 的 status 出现 ACTIVE

SQL> alter system switch logfile;

System altered.

SQL> alter system switch logfile;

System altered.

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

GROUP# SEQUENCE# ARC STATUS

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

1 13 YES ACTIVE

2 14 NO CURRENT

3 12 YES ACTIVE

--模拟 ACTIVE 状态的 redolog 丢失

[oracle@11g orcl]$ rm -rf redo01.log

--数据库状态

[oracle@11g trace]$ tail -f alert_orcl.log

Errors in file /home/oracle/app/diag/rdbms/orcl/orcl/trace/orcl_arc2_23552.trc:

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

ORA-00312: online log 1 thread 1: '/home/oracle/app/oradata/orcl/redo01.log'

ORA-27037: unable to obtain file status

Linux-x86_64 Error: 2: No such file or directory

Additional information: 3

Master background archival failure: 313

SQL> alter system switch logfile; （多次切换redolog，发现多次以后会话 hang 住）

--处理过程

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

GROUP# SEQUENCE# ARC STATUS

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

1 16 NO INACTIVE

2 17 NO INACTIVE

3 18 NO CURRENT

SQL> alter database clear unarchived logfile group 1;

--检查redolog是否正常生成

[oracle@11g orcl]$ ll redo*

-rw-r-----. 1 oracle oinstall 52429312 Mar 25 14:31 redo01.log

-rw-r-----. 1 oracle oinstall 52429312 Mar 25 14:32 redo02.log

-rw-r-----. 1 oracle oinstall 52429312 Mar 25 14:31 redo03.log

--多次切换日志，看数据库是否正常

SQL> alter system switch logfile;

System altered.

SQL> /

System altered.

SQL> /

System altered.

SQL> /

System altered.

OK，一切正常。