<h1 id="1">1.官方文檔描述</h1> 關於Clearing a Redo Log File的官方文檔描述： > A redo log file might become corrupted while the database is open, and ultimately stop database activity because archiving cannot continue. In this situation the ALTER DATABASE CLEAR LOGFILE statement can be used to reinitialize the file without shutting down the database. > > The following statement clears the log files in redo log group number 3: > > ALTER DATABASE CLEAR LOGFILE GROUP 3; > This statement overcomes two situations where dropping redo logs is not possible: > > If there are only two log groups > > The corrupt redo log file belongs to the current group > > If the corrupt redo log file has not been archived, use the UNARCHIVED keyword in the statement. > > ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 3; > This statement clears the corrupted redo logs and avoids archiving them. The cleared redo logs are available for use even though they were not archived. > > If you clear a log file that is needed for recovery of a backup, then you can no longer recover from that backup. The database writes a message in the alert log describing the backups from which you cannot recover.數據庫
Note:oracle
If you clear an unarchived redo log file, you should make another backup of the database. To clear an unarchived redo log that is needed to bring an offline tablespace online, use the UNRECOVERABLE DATAFILE clause in the ALTER DATABASE CLEAR LOGFILE statement.app
If you clear a redo log needed to bring an offline tablespace online, you will not be able to bring the tablespace online again. You will have to drop the tablespace or perform an incomplete recovery. Note that tablespaces taken offline normal do not require recovery.ui
<h1 id="2">2.故障報錯信息</h1> 啓動數據庫在open階段失敗：this
SQL> startup ORACLE instance started. Total System Global Area 313860096 bytes Fixed Size 1344652 bytes Variable Size 205523828 bytes Database Buffers 100663296 bytes Redo Buffers 6328320 bytes Database mounted. ORA-03113: end-of-file on communication channel Process ID: 2039 Session ID: 102 Serial number: 5
進一步查看alert告警日誌發現是redo日誌文件損壞：spa
Mon May 20 01:00:52 2019 alter database open Mon May 20 01:00:52 2019 LGWR: STARTING ARCH PROCESSES Mon May 20 01:00:53 2019 ARC0 started with pid=18, OS id=2389 ARC0: Archival started LGWR: STARTING ARCH PROCESSES COMPLETE ARC0: STARTING ARCH PROCESSES Mon May 20 01:00:54 2019 ARC1 started with pid=19, OS id=2391 Mon May 20 01:00:54 2019 ARC2 started with pid=20, OS id=2393 Incomplete read from log member '/u03/oradata/PROD2/redo01.dbf'. Trying next member. ARCH: All Archive destinations made inactive due to error 333 ARCH: Closing local archive destination LOG_ARCHIVE_DEST_1: '/u01/app/oracle/product/11.2.0/db_1/dbs/arch1_1_1008712962.dbf' (error 333) (PROD2) Committing creation of archivelog '/u01/app/oracle/product/11.2.0/db_1/dbs/arch1_1_1008712962.dbf' (error 333) Mon May 20 01:00:54 2019 ARC3 started with pid=21, OS id=2395 Errors in file /u01/app/oracle/diag/rdbms/prod2/PROD2/trace/PROD2_ora_2179.trc: ORA-16038: log 1 sequence# 1 cannot be archived ORA-00333: redo log read error block count ORA-00312: online log 1 thread 1: '/u03/oradata/PROD2/redo01.dbf' ARC1: Archival started ARC2: Archival started USER (ospid: 2179): terminating the instance due to error 16038 Mon May 20 01:00:55 2019 System state dump requested by (instance=1, osid=2179), summary=[abnormal instance termination]. System State dumped to trace file /u01/app/oracle/diag/rdbms/prod2/PROD2/trace/PROD2_diag_2131.trc Dumping diagnostic data in directory=[cdmp_20190520010055], requested by (instance=1, osid=2179), summary=[abnormal instance termination]. Instance terminated by USER, pid = 2179
<h1 id="3">3.分析解決問題</h1> **3.1 再次嘗試啓動數據庫故障可重現**日誌
SQL> startup mount;
SQL> select checkpoint_change# from v$datafile;
CHECKPOINT_CHANGE#
------------------
2126114
2126114
2126114
2126114
2126114
SQL> select checkpoint_change# from v$datafile_header;
CHECKPOINT_CHANGE#
------------------
2126114
2126114
2126114
2126114
2126114
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel
Process ID: 2179
Session ID: 102 Serial number: 5
3.2 啓動到mount嘗試clear重作日誌文件code
SQL> conn /as sysdba
Connected to an idle instance.
SQL> startup mount;
ORACLE instance started.
Total System Global Area 313860096 bytes
Fixed Size 1344652 bytes
Variable Size 205523828 bytes
Database Buffers 100663296 bytes
Redo Buffers 6328320 bytes
Database mounted.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ ---------
1 1 1 52428800 512 1 NO INACTIVE 2080429 19-MAY-19 2105566 20-MAY-19
3 1 3 52428800 512 1 NO CURRENT 2106113 20-MAY-19 2.8147E+14
2 1 2 52428800 512 1 NO INACTIVE 2105566 20-MAY-19 2106113 20-MAY-19
SQL> alter database clear logfile group 1;
alter database clear logfile group 1
*
ERROR at line 1:
ORA-00350: log 1 of instance PROD2 (thread 1) needs to be archived
ORA-00312: online log 1 thread 1: '/u03/oradata/PROD2/redo01.dbf'
SQL> alter database clear unarchived logfile group 1;
Database altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ ---------
1 1 0 52428800 512 1 YES UNUSED 2080429 19-MAY-19 2105566 20-MAY-19
3 1 3 52428800 512 1 NO CURRENT 2106113 20-MAY-19 2.8147E+14
2 1 2 52428800 512 1 NO INACTIVE 2105566 20-MAY-19 2106113 20-MAY-19
因爲本次3個redo日誌所有確認已損壞，須要依次clear:orm
SQL> alter database clear logfile group 2;
alter database clear logfile group 2
*
ERROR at line 1:
ORA-00350: log 2 of instance PROD2 (thread 1) needs to be archived
ORA-00312: online log 2 thread 1: '/u03/oradata/PROD2/redo02.dbf'
SQL> alter database clear logfile group 3;
alter database clear logfile group 3
*
ERROR at line 1:
ORA-00350: log 3 of instance PROD2 (thread 1) needs to be archived
ORA-00312: online log 3 thread 1: '/u03/oradata/PROD2/redo03.dbf'
SQL> alter database clear unarchived logfile group 2;
Database altered.
SQL> alter database clear unarchived logfile group 3;
Database altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ ---------
1 1 4 52428800 512 1 NO CURRENT 2106114 20-MAY-19 2.8147E+14
3 1 0 52428800 512 1 YES UNUSED 2106113 20-MAY-19 2106114 20-MAY-19
2 1 0 52428800 512 1 YES UNUSED 2105566 20-MAY-19 2106113 20-MAY-19
SQL> alter database open;
Database altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ ---------
1 1 4 52428800 512 1 NO CURRENT 2106114 20-MAY-19 2.8147E+14
2 1 0 52428800 512 1 YES UNUSED 2105566 20-MAY-19 2106113 20-MAY-19
3 1 0 52428800 512 1 YES UNUSED 2106113 20-MAY-19 2106114 20-MAY-19
數據庫開啓後建議儘快從新執行一次全備。文檔