--=========================================
-- Oracle 聯機重做日誌文件(ONLINE LOG FILE)
--=========================================
一、Oracle中的幾類日誌文件
Redo log files -->聯機重做日誌
Archive log files -->歸檔日誌
Alert log files -->告警日誌
Trace files -->跟蹤日誌
user_dump_dest -->用戶跟蹤日誌
backupground_dump_dest -->進程跟蹤日誌
--查看後臺進程相關目錄
SQL> show parameter dump
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
background_core_dump string partial
background_dump_dest string /u01/app/oracle/admin/orcl/bdump
core_dump_dest string /u01/app/oracle/admin/orcl/cdump
max_dump_file_size string UNLIMITED
shadow_core_dump string partial
user_dump_dest string /u01/app/oracle/admin/orcl/udump
關於Oracle 常用目錄及路徑請參考：Oracle 常用目錄結構(10g)
關於Oracle 體系結構請參考：Oracle實例和Oracle數據庫(Oracle體系結構)
二、聯機重做日誌的規劃管理
1.聯機重做日誌
記錄了數據的所有變化(DML,DDL或管理員對數據所作的結構性更改等)
提供恢復機制(對於意外刪除或宕機利用日誌文件實現數據恢復)
可以被分組管理
2.聯機重做日誌組
由一個或多個相同的聯機日誌文件組成一個聯機重做日誌組
至少兩個日誌組，每組一個成員(建議每組兩個成員，分散放開到不同的磁盤)
由LGWR後臺進程同時將日誌內容寫入到一個組的所有成員
LGWR的觸發條件
在事務提交的時候(COMMIT)
Redo Log Buffer 三分之一滿
Redo Log Buffer 多於一兆的變化記錄
在DBWn寫入數據文件之前
3.聯機重做日誌成員
重做日誌組內的每一個聯機日誌文件稱爲一個成員
一個組內的每一個成員具有相同的日誌序列號(log sequence number),且成員的大小相同
每次日誌切換時，Oracle服務器分配一個新的LSN號給即將寫入日誌的日誌文件組
LSN號用於唯一區分每一個聯機日誌組和歸檔日誌
處於歸檔模式的聯機日誌，LSN號在歸檔時也被寫入到歸檔日誌之中
4.日誌文件的工作方式
日誌文件採用按順序循環寫的方式
當一組聯機日誌組寫滿，LGWR則將日誌寫入到下一組，當最後一組寫滿則從第一組開始寫入
寫入下一組的過程稱爲日誌切換
切換時發生檢查點過程
檢查點的信息同時寫入到控制文件
5.聯機日誌文件的規劃
總原則
分散放開，多路複用
日誌所在的磁盤應當具有較高的I/O
一般日誌組大小應滿足自動切換間隔至少15-20分鐘左右業務需求
建議使用rdo結尾的日誌文件名，避免誤刪日誌文件。如redo1.rdo,redo2.rdo
規劃樣例
Redo Log Group1 Redo Log Group2 Redo Log Group3
Member1 Member1 Member1 -->Physical Disk 1
Member2 Member2 Member2 -->Physical Disk 2
Member3 Member3 Member3 -->Physical Disk 3
6.日誌切換和檢查點切換
ALTER SYSTEM SWITCH LOGFILE; --強制手動切換
ALTER SYSTEM CHECKPOINT;
強制設置檢查點間隔
ALTER SYSTEM SET FAST_START_MTTR_TARGET = n
7.添加日誌文件組
ALTER DATABASE ADD LOGFILE [GROUP n]
('$ORACLE_BASE/oradata/u01/logn1.rdo',
'$ORACLE_BASE/oradata/u01/logn2.rdo')
SIZE mM;
8.添加日誌成員
ALTER DATABASE ADD LOGFILE MEMBER
'$ORACLE_BASE/oradata/u01/logn1.rdo' TO GROUP 1,
'$ORACLE_BASE/oradata/u01/logn2.rdo' TO GROUP 2;
9.刪除日誌成員
不能刪除組內的唯一一個成員
不能刪除處於active 和current 狀態組內的成員
刪除處於active 和current 狀態組內的成員，應使用日誌切換使其處於INACTIVE狀態後再刪除
對於組內如果一個成員爲NULL 值，一個爲INVALID，且組處入INACTIVE，僅能刪除INVALID狀態成員
刪除日誌成員，物理文件並沒有真正刪除，需要手動刪除
刪除日誌文件後，控制文件被更新
對於處於歸檔模式下的數據庫，刪除成員時確保日誌已被歸檔，查看v$log視圖獲得歸檔信息
ALTER DATABASE DROP LOGFILE MEMBER '$ORACLE_BASE/oradata/u01/logn1.rdo'
10.刪除日誌組
一個實例至少需要兩個聯機日誌文件組
活動或當前的日誌組不能被刪除
組內成員狀態有NULL 值或INVALID狀態並存，組不可刪除
日誌組被刪除後，物理文件需要手動刪除(對於非OMF)
ALTER DATABASE DROP LOGFILE GROUP n
11.日誌的重定位及重命名
所需權限
ALTER DATABASE 系統權限
複製文件到目的位置操作系統權限(寫權限)
CURRENT狀態組內的成員不能被重命名
建議該行爲之前備份數據庫
重命名或重定位之後建議立即備份控制文件
重定位及重命名的兩種方法
添加一個新成員到日誌組，然後刪除一箇舊的成員
使用ALTER DATABASE RENAME FILE 命令(不區分歸檔與非歸檔模式)
複製聯機日誌文件到新路徑:ho cp <oldfile> <newfile>
執行ALTER DATABASE RENAME FILE '<oldfile>' TO '<newfile>'
對於處於CURRENT狀態的需要改名且不切換的情況下
辦法是切換到MOUNT狀態下再執行上述操作
12.清空日誌文件組
ALTER DATABASE CLEAR LOGIFLE GROUP n
ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP n --使用unarchived 避免歸檔
13.日誌週期循環及切換分析
Group 1 Group 2 Group 3
Current Inactive Inactive
---------- Log Switch -------------
Active Current Inactive
---------- Log Switch -------------
Active Active Current
---------- Log Switch -------------
Current Inactive Inactive
--Active 和Current 稱之爲在一個循環週期之內(按順序寫日誌)
--Inactive 稱爲一個週期之外(一個新的循環)
--新一輪循環開始如在歸檔狀態則先歸檔再清空，否則直接清空日誌
--數據庫啓動時Active 和Current 狀態的日誌不能丟失，否則出錯
14.日誌的監視
查看日誌視圖中的物理日誌文件是否存在、位置、大小等
SELECT 'ho cp '||member FROM v$logfile;
查看日誌文件所處的磁盤空間是否足夠
SQL> ho df -h
查看組內是否存在多個成員，如爲單一成員應考慮增加日誌成員
日誌切換的間隔時間，應滿足15-20分鐘業務需求，如果切換間隔很短，應當增加日誌文件的大小
增加方法，先刪除日誌組，再重建該組(對於current和active的需要切換再做處理)
--查看切換時間間隔(下面的示例中爲手工切換的時間，不作考慮)
SQL> SELECT TO_CHAR(first_time,'yyyy-mm-dd hh24:mi:ss'),group# FROM v$log;
TO_CHAR(FIRST_TIME, GROUP#
------------------- ----------
2010-07-20 09:43:18 1
2010-07-19 22:44:30 2
2010-07-19 22:44:32 3
15.日誌的異常處理(參照演示中9小節)
不一致的情況(啓動時)
ALTER DATABASE CLEAR LOGFILE GROUP n
ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP n
三、與日誌有關的動態性能視圖
V$LOG
V$LOGFILE
V$LOG中STATUS的狀態值
UNUSED: 從未對該聯機日誌寫入任何內容，一般爲新增加聯機日誌文件或是使用resetlog後的狀態
CURRENT：當前重做日誌文件，表示該重做日誌文件爲活動狀態，能夠被打開和關閉
ACTIVE：處於活動狀態，不屬於當前日誌，崩潰恢復需要該狀態，可用於塊恢復，可能歸檔，也可能未歸檔
CLEARING：表示在執行alter database clear logfile命令後正將該日誌重建爲一個空日誌，重建後狀態變爲unused
CLEARING_CURRENT:當前日誌處於關閉線程的清除狀態。如日誌某些故障或寫入新日誌標頭時發生I/O錯誤
INACTIVE:實例恢復不在需要聯機重做文件日誌組，可能歸檔也可能未歸檔
V$LOGFILE中STATUS的狀態值
INVALID :表明該文件不可訪問
STALE :表明文件內容不完全
DELETED : 表明該文件不再使用
NULL ：表明文件正在使用
四、演示
--1.查看當前數據庫的日誌
SQL> SELECT * FROM v$log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 5 52428800 1 NO CURRENT 2758062 19-JUL-10
2 1 3 52428800 2 YES INACTIVE 2695010 16-JUL-10
3 1 4 104857600 2 YES INACTIVE 2716552 18-JUL-10
SQL> SELECT * FROM v$logfile ORDER BY group#;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------- ---
1 ONLINE /u01/app/oracle/oradata/orcl/redo01.log NO
2 STALE ONLINE /u01/app/oracle/oradata/orcl/redo02.log NO
2 STALE ONLINE /u01/app/oracle/oradata/orcl/redo2.log NO
3 STALE ONLINE /u01/app/oracle/oradata/orcl/redo03.log NO
3 STALE ONLINE /u01/app/oracle/oradata/orcl/redo3.log NO
--2.添加日誌組
SQL> SELECT * FROM v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------- ---
2 STALE ONLINE /u01/app/oracle/oradata/orcl/redo2.log NO
2 STALE ONLINE /u01/app/oracle/oradata/orcl/redo02.log NO
1 ONLINE /u01/app/oracle/oradata/orcl/redo01.log NO
3 STALE ONLINE /u01/app/oracle/oradata/orcl/redo3.log NO
3 STALE ONLINE /u01/app/oracle/oradata/orcl/redo03.log NO
4 ONLINE /u01/app/oracle/oradata/orcl/redo4.log NO
4 ONLINE /u01/app/oracle/oradata/orcl/redo04.log NO
--3.添加日誌成員
SQL> ALTER DATABASE ADD LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo1.log' TO GROUP 1;
Database altered.
SQL> SELECT * FROM v$logfile WHERE group# = 1 ;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------- ---
1 ONLINE /u01/app/oracle/oradata/orcl/redo01.log NO
1 INVALID ONLINE /u01/app/oracle/oradata/orcl/redo1.log NO
--4.刪除日誌成員
SQL> ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo01.log';
ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo01.log'
*
ERROR at line 1: --redo01.log處於NULL狀態且該日誌組爲current狀態不能刪除
ORA-00362: member is required to form a valid logfile in group 1
ORA-01517: log member: '/u01/app/oracle/oradata/orcl/redo01.log'
SQL> ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo04.log';
Database altered.
SQL> ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo4.log';
ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo4.log'
*
ERROR at line 1: --最後一個日誌成員不能被刪除
ORA-00361: cannot remove last log member /u01/app/oracle/oradata/orcl/redo4.log for group 4
--5.日誌切換
SQL> SELECT * FROM v$log; --當前的日誌組處於CURRENT狀態
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 5 52428800 2 NO CURRENT 2758062 19-JUL-10
2 1 3 52428800 2 YES INACTIVE 2695010 16-JUL-10
3 1 4 104857600 2 YES INACTIVE 2716552 18-JUL-10
4 1 0 31457280 1 YES UNUSED 0
SQL> ALTER SYSTEM SWITCH LOGFILE; --進行日誌切換
System altered.
SQL> SELECT * FROM v$log; --原來的日誌組4的unused狀態變爲current狀態
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 5 52428800 2 YES ACTIVE 2758062 19-JUL-10
2 1 3 52428800 2 YES INACTIVE 2695010 16-JUL-10
3 1 4 104857600 2 YES INACTIVE 2716552 18-JUL-10
4 1 6 31457280 1 NO CURRENT 2759277 19-JUL-10
SQL> ALTER SYSTEM SWITCH LOGFILE; --再次進行日誌切換
System altered.
SQL> SELECT * FROM v$log; --日誌組1變爲current且組4變爲active 狀態
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 5 52428800 2 YES ACTIVE 2758062 19-JUL-10
2 1 7 52428800 2 NO CURRENT 2759293 19-JUL-10
3 1 4 104857600 2 YES INACTIVE 2716552 18-JUL-10
4 1 6 31457280 1 YES ACTIVE 2759277 19-JUL-10
由上可得知，在日誌切換時對於unused組將優先作爲下一組切換對象
--再次刪除redo01.log還是收到錯誤提示
SQL> ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo01.log';
ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo01.log'
*
ERROR at line 1:
ORA-00362: member is required to form a valid logfile in group 1
ORA-01517: log member: '/u01/app/oracle/oradata/orcl/redo01.log'
SQL> ALTER SYSTEM SWITCH LOGFILE; --再次進行日誌切換
System altered.
SQL> SELECT * FROM v$log; --group1變爲inactive
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 5 52428800 2 YES INACTIVE 2758062 19-JUL-10
2 1 7 52428800 2 YES ACTIVE 2759293 19-JUL-10
3 1 8 104857600 2 NO CURRENT 2759420 19-JUL-10
4 1 6 31457280 1 YES INACTIVE 2759277 19-JUL-10
--反覆多切幾次日誌之後redo01.log被成功刪除
SQL> ALTER DATABASE DROP LOGFILE MEMBER '/u01/app/oracle/oradata/orcl/redo01.log';
Database altered.
--6.刪除日誌組(CURRENT和ACTIVE狀態的不能被刪除)
SQL> SELECT * FROM v$log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 9 52428800 1 YES ACTIVE 2759487 19-JUL-10
2 1 11 52428800 2 NO CURRENT 2759502 19-JUL-10
3 1 8 104857600 2 YES ACTIVE 2759420 19-JUL-10
4 1 10 31457280 1 YES ACTIVE 2759499 19-JUL-10
SQL> ALTER DATABASE DROP LOGFILE GROUP 4;
ALTER DATABASE DROP LOGFILE GROUP 4
*
ERROR at line 1: --處於活動狀態的group4 用於災難恢復，不能被刪除
ORA-01624: log 4 needed for crash recovery of instance orcl (thread 1)
ORA-00312: online log 4 thread 1: '/u01/app/oracle/oradata/orcl/redo4.log'
SQL> ALTER SYSTEM SWITCH LOGFILE; --進行日誌切換
System altered.
SQL> /
System altered.
SQL> SELECT * FROM v$log; --group 4的狀態變爲inactvie
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 13 52428800 1 NO CURRENT 2759720 19-JUL-10
2 1 11 52428800 2 YES ACTIVE 2759502 19-JUL-10
3 1 12 104857600 2 YES ACTIVE 2759718 19-JUL-10
4 1 10 31457280 1 YES INACTIVE 2759499 19-JUL-10
SQL> ALTER DATABASE DROP LOGFILE GROUP 4; --成功刪除group 4
Database altered.
SQL> ho ls /u01/app/oracle/oradata/orcl/redo*
/u01/app/oracle/oradata/orcl/redo01.log /u01/app/oracle/oradata/orcl/redo1.log
/u01/app/oracle/oradata/orcl/redo02.log /u01/app/oracle/oradata/orcl/redo2.log
/u01/app/oracle/oradata/orcl/redo03.log /u01/app/oracle/oradata/orcl/redo3.log
/u01/app/oracle/oradata/orcl/redo04.log /u01/app/oracle/oradata/orcl/redo4.log
SQL> ho rm /u01/app/oracle/oradata/orcl/redo04.log --刪除物理文件
SQL> ho rm /u01/app/oracle/oradata/orcl/redo4.log --刪除物理文件
--7.日誌的重定位及重命名(僅演示ALTER DATABASE RENAME FILE 命令)
SQL> SELECT name,log_mode FROM v$database;
NAME LOG_MODE
--------- ------------
ORCL ARCHIVELOG
SQL> SELECT * FROM v$logfile ORDER BY group#;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------- ---
1 ONLINE /u01/app/oracle/oradata/orcl/redo01.log NO
2 ONLINE /u01/app/oracle/oradata/orcl/redo02.log NO
2 ONLINE /u01/app/oracle/oradata/orcl/redo2.log NO
3 STALE ONLINE /u01/app/oracle/oradata/orcl/redo03.log NO
3 STALE ONLINE /u01/app/oracle/oradata/orcl/redo3.log NO
SQL> ho cp /u01/app/oracle/oradata/orcl/redo01.log /u01/app/oracle/oradata/redo01.rdo
SQL> ALTER DATABASE RENAME FILE '/u01/app/oracle/oradata/orcl/redo01.log'
2 TO '/u01/app/oracle/oradata/redo01.rdo';
Database altered.
SQL> SELECT * FROM v$logfile WHERE group# = 1;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------- ---
1 ONLINE /u01/app/oracle/oradata/redo01.rdo NO
--8.清空日誌文件組(只有非active 和非current狀態的組才能被清空)
SQL> SELECT * FROM v$log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 13 52428800 1 YES ACTIVE 2759720 19-JUL-10
2 1 14 52428800 2 NO CURRENT 2761383 19-JUL-10
3 1 12 104857600 2 YES INACTIVE 2759718 19-JUL-10
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;
ALTER DATABASE CLEAR LOGFILE GROUP 1
*
ERROR at line 1: --active 狀態不能被清空
ORA-01624: log 1 needed for crash recovery of instance orcl (thread 1)
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/redo1.rdo'
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 2;
ALTER DATABASE CLEAR LOGFILE GROUP 2
*
ERROR at line 1: --current 狀態不能被清空
ORA-01624: log 2 needed for crash recovery of instance orcl (thread 1)
ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/orcl/redo2.log'
ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/orcl/redo02.log'
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 3;
Database altered.
SQL> SELECT * FROM v$log; --group 3被清空後狀態變爲unused
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 13 52428800 1 YES INACTIVE 2759720 19-JUL-10
2 1 14 52428800 2 NO CURRENT 2761383 19-JUL-10
3 1 0 104857600 2 YES UNUSED 2759718 19-JUL-10
--9.日誌異常處理
--啓動時提示日誌不一致
SQL> startup
ORACLE instance started.
Total System Global Area 251658240 bytes
Fixed Size 1218796 bytes
Variable Size 83887892 bytes
Database Buffers 163577856 bytes
Redo Buffers 2973696 bytes
Database mounted.
ORA-00341:log 1 of thread 1,wrong log # in header
ORA-00312:online log 1 thread 1:'/u01/app/oracle/oradata/orcl/redo1a.rdo'
ORA-00312:online log 1 thread 1:'/u01/app/oracle/oradata/orcl/redo1b.rdo'
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;
Database altered.
SQL> ALTER DATABASE OPEN;
Database opened.
--日誌文件丟失(非current狀態日誌組)
SQL> startup
ORACLE instance started.
Total System Global Area 251658240 bytes
Fixed Size 1218796 bytes
Variable Size 88082196 bytes
Database Buffers 159383552 bytes
Redo Buffers 2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo1a.rdo'
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo1b.rdo'
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;
Database altered.
SQL> ALTER DATABASE OPEN;
Database altered.
--日誌文件丟失(current狀態日誌組)
SQL> startup
ORACLE instance started.
Total System Global Area 251658240 bytes
Fixed Size 1218796 bytes
Variable Size 83887892 bytes
Database Buffers 163577856 bytes
Redo Buffers 2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3a.rdo'
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3b.rdo'
--查看告警日誌
SQL> ho tail -n 30 /u01/app/oracle/admin/orcl/bdump/alert_orcl.log
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3a.rdo'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Tue Jul 20 10:45:58 2010
Errors in file /u01/app/oracle/admin/orcl/bdump/orcl_lgwr_4112.trc:
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3b.rdo'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3a.rdo'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Tue Jul 20 10:45:58 2010
ARC0: STARTING ARCH PROCESSES
Tue Jul 20 10:45:58 2010
ARC1: Becoming the 'no FAL' ARCH
ARC1: Becoming the 'no SRL' ARCH
Tue Jul 20 10:45:58 2010
ARC2: Archival started
ARC0: STARTING ARCH PROCESSES COMPLETE
ARC0: Becoming the heartbeat ARCH
ARC2 started with pid=18, OS id=4137
Tue Jul 20 10:45:58 2010
ORA-313 signalled during: ALTER DATABASE OPEN...
--查看物理日誌文件是否存在
SQL> ho ls /u01/app/oracle/oradata/orcl/redo3a.rdo
ls: /u01/app/oracle/oradata/orcl/redo3a.rdo: No such file or directory
SQL> ho ls /u01/app/oracle/oradata/orcl/redo3b.rdo
ls: /u01/app/oracle/oradata/orcl/redo3b.rdo: No such file or directory
--嘗試使用清空日誌組命令
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 3;
ALTER DATABASE CLEAR LOGFILE GROUP 3
*
ERROR at line 1: --系統處於非歸檔模式，且group 3狀態爲CURRENT
ORA-00350: log 3 of instance orcl (thread 1) needs to be archived
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3a.rdo'
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3b.rdo'
--嘗試使用不歸檔清空日誌
SQL> ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 3;
ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 3
*
ERROR at line 1:
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3b.rdo'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/orcl/redo3a.rdo'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
--使用帶控制文件的介質恢復
SQL> RECOVER DATABASE USING BACKUP CONTROLFILE;
ORA-00279: change 2835232 generated at 07/20/2010 10:40:23 needed for thread 1
ORA-00289: suggestion : /u01/app/oracle/flash_recovery_area/ORCL/archivelog/2010_07_20/o1_mf_1_39_%u_.arc
ORA-00280: change 2835232 for thread 1 is in sequence #39
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
ORA-00308: cannot open archived log '/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2010_07_20/o1_mf_1_39_%u_.arc'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
--使用resetlogs選項打開數據庫
SQL> ALTER DATABASE OPEN RESETLOGS;
Database altered.
SQL> SELECT * FROM v$log; --系統重建group 3
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 2 31457280 2 NO CURRENT 2835234 20-JUL-10
2 1 1 31457280 2 YES INACTIVE 2835233 20-JUL-10
3 1 0 31457280 2 YES UNUSED 0
SQL> SELECT * FROM v$logfile; --爲group 3增加了兩個成員redo3a.rdo ，redo3b.rdo
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------- ---
2 ONLINE /u01/app/oracle/oradata/orcl/redo2a.rdo NO
2 ONLINE /u01/app/oracle/oradata/orcl/redo2b.rdo NO
1 ONLINE /u01/app/oracle/oradata/orcl/redo1a.rdo NO
3 ONLINE /u01/app/oracle/oradata/orcl/redo3a.rdo NO
3 ONLINE /u01/app/oracle/oradata/orcl/redo3b.rdo NO
1 ONLINE /u01/app/oracle/oradata/orcl/redo1b.rdo NO
對於CURRENT組的也可以使用隱藏參數來解決
步驟：
alter system set "_allow_resetlogs_corruption" = true scope = spfile;
recover database using bakcup controlfile;
alter database open resetlogs;
shutdown immediate;
startup mount;
alter database open resetlogs;
alter system reset "_allow_resetlogs_corruption" scope = spfile sid = '*'
對於歸檔模式下的日誌文件丟失，同樣可以按上述步驟處理