實驗環境
- 作業系統 Redhat5.4 x86
- 資料庫版本 oracle 11gR2 (11.2.0.1.0)
- 資料庫為未開啟歸檔模式
[[email protected] ~]$ sqlplus / as sysdba
SQL*Plus: Release .. Production on Sun May ::
Copyright (c) , , Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
Database opened.
SQL> archive log list
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence
Current log sequence
SQL> select LOG_MODE,OPEN_MODE,FORCE_LOGGING from v$database;
LOG_MODE OPEN_MODE FOR
------------ -------------------- ---
NOARCHIVELOG READ WRITE NO
實驗模拟
1.redo日志組中部分member檔案丢失或損壞
redo日志組部分member檔案丢失,無論目前日志組是inactive, active(非current,current)都不會造成資料丢失,恢複方法也相同,是以不做特别區分。
詳細參見:http://blog.csdn.net/zhuke0203/article/details/71311993#t2
案例模拟
SQL> set line
SQL> col member for a60
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
ONLINE /u01/app/oracle/oradata/PROD1/disk1/redo01a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo01b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo02a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo02b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo03a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk4/redo03b.log NO
rows selected.
SQL> select group#,sequence#, members, archived, status from v$log;
GROUP# SEQUENCE# MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
NO INACTIVE
NO INACTIVE
NO CURRENT
SQL> !rm /u01/app/oracle/oradata/PROD1/disk1/redo01a.log
SQL> startup force;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
Database opened.
--資料庫可以正常啟動,alert日志會有相關報錯資訊:
Sun May ::
db_recovery_file_dest_size of MB is % used. This is a
user-specified limit on the amount of space that will be used by this
database for recovery-related files, and does not reflect the amount of
space available in the underlying filesystem or ASM diskgroup.
Errors in file /u01/app/oracle/diag/rdbms/prod1/PROD1/trace/PROD1_m000_8957.trc:
ORA-: log of thread is more recent than control file
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk2/redo01b.log'
Errors in file /u01/app/oracle/diag/rdbms/prod1/PROD1/trace/PROD1_m000_8957.trc:
ORA-: open failed for members of log group of thread
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk1/redo01a.log'
ORA-: unable to obtain file status
Linux Error: : No such file or directory
Additional information:
Checker run found new persistent data failures
案例恢複
由于損壞的隻是日志組中的部分member,是以可以将損壞的member file檔案删除以後重新添加進來:
SQL> alter database drop logfile member '/u01/app/oracle/oradata/PROD1/disk1/redo01a.log';
alter database drop logfile member '/u01/app/oracle/oradata/PROD1/disk1/redo01a.log'
*
ERROR at line :
ORA-: log is the current log for thread - cannot drop members
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk1/redo01a.log'
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk2/redo01b.log'
SQL> alter system switch logfile;
System altered.
SQL> select group#, sequence#, members, archived, status from v$log;
GROUP# SEQUENCE# MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
NO ACTIVE
NO CURRENT
NO INACTIVE
SQL> alter database drop logfile member '/u01/app/oracle/oradata/PROD1/disk1/redo01a.log';
Database altered.
SQL> alter database add logfile member '/u01/app/oracle/oradata/PROD1/disk1/redo01a.log' reuse to group ;
Database altered.
SQL> !ls -la /u01/app/oracle/oradata/PROD1/disk1/redo01a.log
-rw-r----- oracle oinstall May : /u01/app/oracle/oradata/PROD1/disk1/redo01a.log
這種情況資料庫可以正常啟動,不會造成資料丢失。
2.非active redo日志組中所有member檔案都丢失或損壞
案例模拟
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
INVALID ONLINE /u01/app/oracle/oradata/PROD1/disk1/redo01a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo01b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo02a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo02b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo03a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk4/redo03b.log NO
rows selected.
SQL> select group#, sequence#, members, archived, status from v$log;
GROUP# SEQUENCE# MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
NO ACTIVE
NO CURRENT
NO INACTIVE
SQL> !rm /u01/app/oracle/oradata/PROD1/disk3/redo03a.log /u01/app/oracle/oradata/PROD1/disk4/redo03b.log
SQL> startup force;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
ORA-: end-of-file on communication channel
Process ID:
Session ID: Serial number:
案例恢複
SQL> conn / as sysdba
Connected to an idle instance.
SQL> startup mount;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
SQL> set line
SQL> col member for a60
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
INVALID ONLINE /u01/app/oracle/oradata/PROD1/disk1/redo01a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo01b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo02a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo02b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo03a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk4/redo03b.log NO
rows selected.
SQL> select group#, sequence#, members, archived, status from v$log;
GROUP# SEQUENCE# MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
NO INACTIVE
NO INACTIVE
NO CURRENT
SQL> alter database clear logfile group ;
Database altered.
SQL> alter database open;
Database altered.
SQL> select status from v$instance;
STATUS
------------
OPEN
這種情況資料庫無法正常啟動,恢複不會造成資料丢失。
3.active redo日志組中所有member檔案都丢失或損壞
ACTIVE redo日志組無論是否為current狀态,恢複方法相同。
案例模拟
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
ONLINE /u01/app/oracle/oradata/PROD1/disk1/redo01a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo01b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo02a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo02b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo03a.log NO
INVALID ONLINE /u01/app/oracle/oradata/PROD1/disk4/redo03b.log NO
rows selected.
SQL> select group#, sequence#, members, archived, status from v$log;
GROUP# SEQUENCE# MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
NO CURRENT
NO INACTIVE
NO ACTIVE
SQL> !rm /u01/app/oracle/oradata/PROD1/disk3/redo03a.log /u01/app/oracle/oradata/PROD1/disk4/redo03b.log
SQL> startup force;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
ORA-: open failed for members of log group of thread
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk3/redo03a.log'
ORA-: unable to obtain file status
Linux Error: : No such file or directory
Additional information:
案例恢複
SQL> select status from v$instance;
STATUS
------------
MOUNTED
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
ONLINE /u01/app/oracle/oradata/PROD1/disk1/redo01a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo01b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo02a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo02b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo03a.log NO
INVALID ONLINE /u01/app/oracle/oradata/PROD1/disk4/redo03b.log NO
rows selected.
SQL> select group#, sequence#, members, archived, status from v$log;
GROUP# SEQUENCE# MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
NO CURRENT
NO ACTIVE
NO INACTIVE
--嘗試clear日志組:
SQL> alter database clear logfile group ;
alter database clear logfile group
*
ERROR at line :
ORA-: log needed for crash recovery of instance PROD1 (thread )
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk3/redo03a.log'
ORA-: online log thread : '/u01/app/oracle/oradata/PROD1/disk4/redo03b.log'
--嘗試recover database:
SQL> recover database using backup controlfile;
ORA-: change generated at // :: needed for thread
ORA-: suggestion : /u01/app/oracle/flash_recovery_area/PROD1/archivelog/_05_07/o1_mf_1_24_%u_.arc
ORA-: change for thread is in sequence #24
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
ORA-: cannot open archived log '/u01/app/oracle/flash_recovery_area/PROD1/archivelog/_05_07/o1_mf_1_24_%u_.arc'
ORA-: unable to obtain file status
Linux Error: : No such file or directory
Additional information:
--嘗試resetlogs:
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line :
ORA-: file needs media recovery
ORA-: data file : '/u01/app/oracle/oradata/PROD1/disk1/system01.dbf'
--嘗試設定隐藏參數,讓資料庫跳過一緻性檢查:
SQL> alter system set "_allow_resetlogs_corruption"=true scope=spfile;
System altered.
SQL> shutdown immediate;
ORA-: database not open
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
SQL> alter database open resetlogs;
Database altered.
--将隐藏參數重置回預設值:
SQL> alter system reset "_allow_resetlogs_corruption";
System altered.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.
Total System Global Area bytes
Fixed Size bytes
Variable Size bytes
Database Buffers bytes
Redo Buffers bytes
Database mounted.
Database opened.
SQL>
SQL> select status from v$instance;
STATUS
------------
OPEN
SQL> set line
SQL> col member for a60
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo01b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk1/redo01a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk2/redo02a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo02b.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk3/redo03a.log NO
ONLINE /u01/app/oracle/oradata/PROD1/disk4/redo03b.log NO
rows selected.
SQL> select group#, members, sequence#, archived, status from v$log;
GROUP# MEMBERS SEQUENCE# ARC STATUS
---------- ---------- ---------- --- ----------------
NO CURRENT
YES UNUSED
YES UNUSED
--注:這種方法慎用,隻有當其它方法都嘗試了無效,作為最後一種嘗試的時候使用,設定隐藏參數有可能造成意想不到的後果。
該情況下,資料庫無法正常啟動,會造成部分資料丢失。