一、實驗目的
本篇主要模擬控制文件丟失後，如何根據實際情況恢復數據庫，才能使數據庫儘可能不丟失數據。
二、實驗環境
1）Linux系統環境
[oracle@DG1 ~]$ lsb_release -a LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1-noarch Distributor ID: RedHatEnterpriseServer Description: Red Hat Enterprise Linux Server release 5.4 (Tikanga) Release: 5.4 Codename: Tikanga
2）Oracle數據庫版本信息
SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod PL/SQL Release 10.2.0.1.0 - Production CORE 10.2.0.1.0 Production TNS for Linux: Version 10.2.0.1.0 - Production NLSRTL Version 10.2.0.1.0 – Production
3）查看數據庫是否歸檔
[oracle@DG1 ~]$sqlplus / as sysdba SQL> archive logfile list; SP2-0734: unknown command beginning "archive lo..." - rest of line ignored. SQL> archive list; SP2-0734: unknown command beginning "archive li..." - rest of line ignored. SQL> archive log list Database log mode Archive Mode Automatic archival Enabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 1 Next log sequence to archive 1 Current log sequence 1
三、實驗模擬種類及解決方案
1）丟失部分控制文件，其餘控制文件還在
解決方案：一致性關庫後，通過copy剩下的控制文件恢復
2）在無備份的情況下丟失了所有的控制文件，但對控制文做了追蹤備份
解決方案：通過相應的trace文件，生成腳本，重新創建controlfile
3）在歸檔模式下，對數據庫有完備，丟失全部控制文件
解決方案：通過備份集中的控制文件進行恢復
四、實驗過程
1）丟失部分控制文件，其餘控制文件還在
查看數據庫中控制文件
SQL> select '!rm '||name from v$controlfile; '!RM '||NAME ------------------------------------------------------------------------------- !rm /u01/app/oracle/oradata/lzcdb/control01.ctl !rm /u01/app/oracle/oradata/lzcdb/control02.ctl !rm /u01/app/oracle/oradata/lzcdb/control03.ctl
刪除control02.ctl和control03.ctl控制文件
SQL> !rm /u01/app/oracle/oradata/lzcdb/control02.ctl !rm /u01/app/oracle/oradata/lzcdb/control03.ctl
查看控制文件
SQL> !ls /u01/app/oracle/oradata/DG1/ control01.ctl redo01.log redo02.log redo03.log system01.dbf undotbs01.dbf redo01_a.log redo02_a.log redo03_a.log sysaux01.dbf temp01.dbf users01.dbf
關閉數據庫再重新啓動數據庫（關閉時要執行一致性關閉）
SQL> shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down.
重新啓動數據庫
SQL> startup ORACLE instance started. Total System Global Area 285212672 bytes Fixed Size 1218992 bytes Variable Size 88082000 bytes Database Buffers 192937984 bytes Redo Buffers 2973696 bytes ORA-00205: error in identifying control file, check alert log for more info
警告日誌信息如下
Wed Jun 13 23:38:18 2012
ALTER DATABASE MOUNT
Wed Jun 13 23:38:18 2012
ORA-00202: control file: '/u01/app/oracle/oradata/DG1/control02.ctl'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Wed Jun 13 23:38:18 2012
ORA-205 signalled during: ALTER DATABASE MOUNT在由nomount啓動到mount時錯誤
解決方案：將數據庫一致性關閉之後把control01.ctl複製兩份，然後改名成刪除的控制文件
SQL> shutdownimmediate; ORA-01507: databasenot mounted ORACLE instance shutdown. SQL> !cp/u01/app/oracle/oradata/lzcdb/control01.ctl/u01/app/oracle/oradata/lzcdb/control02.ctl SQL> !cp/u01/app/oracle/oradata/lzcdb/control01.ctl/u01/app/oracle/oradata/lzcdb/control03.ctl
再次重新啓動數據庫
SQL> startup ORACLE instancestarted. Total System GlobalArea 285212672 bytes Fixed Size 1218992 bytes Variable Size 83887696 bytes DatabaseBuffers 197132288 bytes Redo Buffers 2973696 bytes Database mounted. Database opened.
成功啓動！這種恢復控制文件，一定要在控制文件丟失後一致性關閉數據庫，這樣才能保證恢復出的控制文件課數據文件的SCN一致，打開數據庫是不會出錯（但如果是在歸檔模式子，即便不一致性關庫，通過此方式也應該能恢復數據庫吧！但我還沒做實驗驗證！）。
2）在沒有備份的情況下丟失了所有的控制文件，但是對控制文件做了追蹤備份
在這裏羅嗦一點，注意一定要先將控制文件做追蹤備份到trace文件中，才能刪除全部控制，否則你刪除全部控制文件，數據庫必然掛掉了，你怎麼可能再去將控制文件做追蹤備份到trace文件中呢？千萬不要犯這樣的低級錯誤。
將控制文件備份到跟蹤文件
SQL> alter database backup controlfile to trace; Database altered.
查看跟蹤文件的位置
SQL> show parameter user; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ license_max_users integer 0 parallel_adaptive_multi_user boolean TRUE user_dump_dest string /u01/app/oracle/admin/DG1/udump
找到剛剛生成的trace文件，將trace文件中創建控制文件的sql語句讀取出來
[oracle@DG1 ~]$ cd /u01/app/oracle/admin/ dataguard1/ DG1/ [oracle@DG1 ~]$ cd /u01/app/oracle/admin/DG1/udump/ [oracle@DG1 udump]$ ls -lrt|tail -1 -rw-r----- 1 oracle oinstall 8397 Jun 13 23:04 dg1_ora_30712.trc
查看生成的讀取的trace內容
[oracle@DG1 udump]$ cat dg1_ora_30712.trc
/u01/app/oracle/admin/DG1/udump/dg1_ora_30712.trc
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
ORACLE_HOME = /u01/app/oracle/product/10.2.0.1/db_1
System name: Linux
Node name: DG1
Release: 2.6.18-164.el5
Version: #1 SMP Tue Aug 18 15:51:54 EDT 2009
Machine: i686
Instance name: DG1
Redo thread mounted by this instance: 1
Oracle process number: 15
Unix process pid: 30712, image: oracle@DG1 (TNS V1-V3)
*** SERVICE NAME:(SYS$USERS) 2012-06-13 23:04:23.363
*** SESSION ID:(159.3) 2012-06-13 23:04:23.363
*** 2012-06-13 23:04:23.363
-- The following are current System-scope REDO Log Archival related
-- parameters and can be included in the database initialization file.
--
-- LOG_ARCHIVE_DEST=''
-- LOG_ARCHIVE_DUPLEX_DEST=''
--
-- LOG_ARCHIVE_FORMAT=%t_%s_%r.dbf
--
-- DB_UNIQUE_NAME="DG1"
--
-- LOG_ARCHIVE_CONFIG='SEND, RECEIVE, NODG_CONFIG'
-- LOG_ARCHIVE_MAX_PROCESSES=2
-- STANDBY_FILE_MANAGEMENT=MANUAL
-- STANDBY_ARCHIVE_DEST=?/dbs/arch
-- FAL_CLIENT=''
-- FAL_SERVER=''
--
-- LOG_ARCHIVE_DEST_10='LOCATION=USE_DB_RECOVERY_FILE_DEST'
-- LOG_ARCHIVE_DEST_10='OPTIONAL REOPEN=300 NODELAY'
-- LOG_ARCHIVE_DEST_10='ARCH NOAFFIRM NOEXPEDITE NOVERIFY SYNC'
-- LOG_ARCHIVE_DEST_10='REGISTER NOALTERNATE NODEPENDENCY'
-- LOG_ARCHIVE_DEST_10='NOMAX_FAILURE NOQUOTA_SIZE NOQUOTA_USED NODB_UNIQUE_NAME'
-- LOG_ARCHIVE_DEST_10='VALID_FOR=(PRIMARY_ROLE,ONLINE_LOGFILES)'
-- LOG_ARCHIVE_DEST_STATE_10=ENABLE
--
-- Below are two sets of SQL statements, each of which creates a new
-- control file and uses it to open the database. The first set opens
-- the database with the NORESETLOGS option and should be used only if
-- the current versions of all online logs are available. The second
-- set opens the database with the RESETLOGS option and should be used
-- if online logs are unavailable.
-- The appropriate set of statements can be copied from the trace into
-- a script file, edited as necessary, and executed when there is a
-- need to re-create the control file.
--
-- Set #1. NORESETLOGS case
--
-- The following commands will create a new control file and use it
-- to open the database.
-- Data used by Recovery Manager will be lost.
-- Additional logs may be required for media recovery of offline
-- Use this only if the current versions of all online logs are
-- available.
-- After mounting the created controlfile, the following SQL
-- statement will place the database in the appropriate
-- protection mode:
-- ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE
STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "DG1" NORESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 (
'/u01/app/oracle/oradata/DG1/redo01.log',
'/u01/app/oracle/oradata/DG1/redo01_a.log'
) SIZE 50M,
GROUP 2 (
'/u01/app/oracle/oradata/DG1/redo02.log',
'/u01/app/oracle/oradata/DG1/redo02_a.log'
) SIZE 50M,
GROUP 3 (
'/u01/app/oracle/oradata/DG1/redo03.log',
'/u01/app/oracle/oradata/DG1/redo03_a.log'
) SIZE 50M
-- STANDBY LOGFILE
DATAFILE
'/u01/app/oracle/oradata/DG1/system01.dbf',
'/u01/app/oracle/oradata/DG1/undotbs01.dbf',
'/u01/app/oracle/oradata/DG1/sysaux01.dbf',
'/u01/app/oracle/oradata/DG1/users01.dbf',
'/u01/app/oracle/product/10.2.0.1/db_1/dbs/soe.dbf'
CHARACTER SET US7ASCII
;
-- Configure RMAN configuration record 1
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('CHANNEL','DEVICE TYPE DISK FORMAT ''/home/oracle/DiskBackupLocation/%U''');
-- Configure RMAN configuration record 2
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('CONTROLFILE AUTOBACKUP','ON');
-- Configure RMAN configuration record 3
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE','DISK TO ''/home/oracle/DiskBackupLocation/%F''');
-- Configure RMAN configuration record 4
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('RETENTION POLICY','TO NONE');
-- Commands to re-create incarnation table
-- Below log names MUST be changed to existing filenames on
-- disk. Any one log file from each branch can be used to
-- re-create incarnation records.
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/FlashRecovery/DG1/archivelog/2012_06_13/o1_mf_1_1_%u_.arc';
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/FlashRecovery/DG1/archivelog/2012_06_13/o1_mf_1_1_%u_.arc';
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/FlashRecovery/DG1/archivelog/2012_06_13/o1_mf_1_1_%u_.arc';
-- Recovery is required if any of the datafiles are restored backups,
-- or if the last shutdown was not normal or immediate.
RECOVER DATABASE
-- All logs need archiving and a log switch is needed.
ALTER SYSTEM ARCHIVE LOG ALL;
-- Database can now be opened normally.
ALTER DATABASE OPEN;
-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/u01/app/oracle/oradata/DG1/temp01.dbf'
SIZE 419430400 REUSE AUTOEXTEND ON NEXT 655360 MAXSIZE 32767M;
-- End of tempfile additions.
--
-- Set #2. RESETLOGS case
--
-- The following commands will create a new control file and use it
-- to open the database.
-- Data used by Recovery Manager will be lost.
-- The contents of online logs will be lost and all backups will
-- be invalidated. Use this only if online logs are damaged.
-- After mounting the created controlfile, the following SQL
-- statement will place the database in the appropriate
-- protection mode:
-- ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE
STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "DG1" RESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 (
'/u01/app/oracle/oradata/DG1/redo01.log',
'/u01/app/oracle/oradata/DG1/redo01_a.log'
) SIZE 50M,
GROUP 2 (
'/u01/app/oracle/oradata/DG1/redo02.log',
'/u01/app/oracle/oradata/DG1/redo02_a.log'
) SIZE 50M,
GROUP 3 (
'/u01/app/oracle/oradata/DG1/redo03.log',
'/u01/app/oracle/oradata/DG1/redo03_a.log'
) SIZE 50M
-- STANDBY LOGFILE
DATAFILE
'/u01/app/oracle/oradata/DG1/system01.dbf',
'/u01/app/oracle/oradata/DG1/undotbs01.dbf',
'/u01/app/oracle/oradata/DG1/sysaux01.dbf',
'/u01/app/oracle/oradata/DG1/users01.dbf',
'/u01/app/oracle/product/10.2.0.1/db_1/dbs/soe.dbf'
CHARACTER SET US7ASCII
;
-- Configure RMAN configuration record 1
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('CHANNEL','DEVICE TYPE DISK FORMAT ''/home/oracle/DiskBackupLocation/%U''');
-- Configure RMAN configuration record 2
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('CONTROLFILE AUTOBACKUP','ON');
-- Configure RMAN configuration record 3
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE','DISK TO ''/home/oracle/DiskBackupLocation/%F''');
-- Configure RMAN configuration record 4
VARIABLE RECNO NUMBER;
EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG('RETENTION POLICY','TO NONE');
-- Commands to re-create incarnation table
-- Below log names MUST be changed to existing filenames on
-- disk. Any one log file from each branch can be used to
-- re-create incarnation records.
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/FlashRecovery/DG1/archivelog/2012_06_13/o1_mf_1_1_%u_.arc';
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/FlashRecovery/DG1/archivelog/2012_06_13/o1_mf_1_1_%u_.arc';
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/FlashRecovery/DG1/archivelog/2012_06_13/o1_mf_1_1_%u_.arc';
-- Recovery is required if any of the datafiles are restored backups,
-- or if the last shutdown was not normal or immediate.
RECOVER DATABASE USING BACKUP CONTROLFILE
-- Database can now be opened zeroing the online logs.
ALTER DATABASE OPEN RESETLOGS;
-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/u01/app/oracle/oradata/DG1/temp01.dbf'
SIZE 419430400 REUSE AUTOEXTEND ON NEXT 655360 MAXSIZE 32767M;
-- End of tempfile additions.
--創建用於恢復控制文件的sql腳本
[oracle@DG1 udump]$ vi dg1_ora_30712.trc ：set nu 53,125 w! /home/oracle/controlfile_trace1_1.sql
查看用於恢復控制文件的sql腳本
[oracle@DG1 ~]$ ls 10201_database_linux32.zip database DiskBackupLocation controlfile_trace1_1.sql Desktop FlashRecovery
刪除所有控制文件
SQL> select '!rm '||name from v$controlfile; '!RM'||NAME ------------------------------------------------------------------------------- !rm/u01/app/oracle/oradata/lzcdb/control01.ctl !rm/u01/app/oracle/oradata/lzcdb/control02.ctl !rm/u01/app/oracle/oradata/lzcdb/control03.ctl SQL> !rm /u01/app/oracle/oradata/DG1/control01.ctl !rm /u01/app/oracle/oradata/DG1/control02.ctl !rm /u01/app/oracle/oradata/DG1/control03.ctl
查看控制文件是否被刪除
SQL> !ls /u01/app/oracle/oradata/DG1/ redo01_a.log redo02_a.log redo03_a.log sysaux01.dbf temp01.dbf users01.dbf redo01.log redo02.log redo03.log system01.dbf undotbs01.dbf
關閉數據庫
SQL> shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down.
重新啓動
SQL> startup ORACLE instance started. Total System Global Area 285212672 bytes Fixed Size 1218992 bytes Variable Size 83887696 bytes Database Buffers 197132288 bytes Redo Buffers 2973696 bytes ORA-00205: error in identifying control file, check alert log for more info
警告日誌出現如下錯誤
Wed Jun 13 23:20:37 2012
ALTER DATABASE MOUNT
Wed Jun 13 23:20:37 2012
ORA-00202: control file: '/u01/app/oracle/oradata/DG1/control01.ctl'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Wed Jun 13 23:20:40 2012
ORA-205 signalled during: ALTER DATABASE MOUNT...
現在解決問題
將實例關閉，執行上面創建的恢復控制文件的腳本controlfile_trace1_1.sql
SQL> @controlfile_trace1_1.sql ORACLE instance started. Total System Global Area 285212672 bytes Fixed Size 1218992 bytes Variable Size 83887696 bytes Database Buffers 197132288 bytes Redo Buffers 2973696 bytes Control file created. PL/SQL procedure successfully completed. PL/SQL procedure successfully completed. PL/SQL procedure successfully completed. PL/SQL procedure successfully completed. ORA-00283: recovery session canceled due to errors ORA-00264: no recovery required ALTER SYSTEM ARCHIVE LOG ALL * ERROR at line 1: ORA-00271: there are no logs that need archiving Database altered. Tablespace altered.
恢復成功
查看數據庫當前狀態
SQL> selectstatus from v$instance STATUS ------------ OPEN
恢復成功！爲了確保數據不丟失，我們應該定期將控制文件做追蹤備份到trace文件，生成恢復控制文件的sql腳本，以防控制文件全部丟失之後，在沒有歸檔模式下的全備份，我們可以通過這種方法恢復數據庫。
3）在歸檔模式下，對數據庫有完備，丟失全部控制文件
注意這裏一定要清楚自己備份集中控制文件備份存放的位置，否則當你幹掉全部控制文件後，進入RMAN模式是在NOMOUNT狀態，此時你無法查用RMAN來看備份集中控制文件的備份位置，更何談用備份集中的控制文件來恢復幹掉的所有控制文件然後再恢復數據庫。
先進入RMAN模式查看備份集中控制文件存放的位置
[oracle@DG1 ~]$ rman target sys/oracle@DG1 Recovery Manager: Release 10.2.0.1.0 - Production on Wed Jun 13 22:09:16 2012 Copyright (c) 1982, 2005, Oracle. All rights reserved. connected to target database: DG1 (DBID=1762320829) RMAN> list backup; List of Backup Sets =================== BS Key Type LV Size Device Type Elapsed Time Completion Time ------- ---- -- ---------- ----------- ------------ --------------- 2 Incr 0 3.39G DISK 00:08:22 13-JUN-12 BP Key: 2 Status: AVAILABLE Compressed: NO Tag: BACKUP_DG1_000001_061312022053 Piece Name: /home/oracle/DiskBackupLocation/02ndeh2i_1_1 List of Datafiles in backup set 2 File LV Type Ckp SCN Ckp Time Name ---- -- ---- ---------- --------- ---- 1 0 Incr 675126 13-JUN-12 /u01/app/oracle/oradata/DG1/system01.dbf 2 0 Incr 675126 13-JUN-12 /u01/app/oracle/oradata/DG1/undotbs01.dbf 3 0 Incr 675126 13-JUN-12 /u01/app/oracle/oradata/DG1/sysaux01.dbf 4 0 Incr 675126 13-JUN-12 /u01/app/oracle/oradata/DG1/users01.dbf 5 0 Incr 675126 13-JUN-12 /u01/app/oracle/product/10.2.0.1/db_1/dbs/soe.dbf BS Key Type LV Size Device Type Elapsed Time Completion Time ------- ---- -- ---------- ----------- ------------ --------------- 3 Full 7.08M DISK 00:00:05 13-JUN-12 BP Key: 3 Status: AVAILABLE Compressed: NO Tag: TAG20120613T142932 Piece Name: /home/oracle/DiskBackupLocation/c-1762320829-20120613-00 Control File Included: Ckp SCN: 677193 Ckp time: 13-JUN-12 SPFILE Included: Modification time: 13-JUN-12 BS Key Size Device Type Elapsed Time Completion Time ------- ---------- ----------- ------------ --------------- 4 1.14G DISK 00:03:47 13-JUN-12 BP Key: 4 Status: AVAILABLE Compressed: NO Tag: BACKUP_DG1_000001_061312022053 Piece Name: /home/oracle/DiskBackupLocation/04ndehir_1_1 List of Archived Logs in backup set 4 Thrd Seq Low SCN Low Time Next SCN Next Time ---- ------- ---------- --------- ---------- --------- 1 6 524597 20-MAY-12 528875 13-JUN-12 1 7 528875 13-JUN-12 528877 13-JUN-12 1 8 528877 13-JUN-12 528880 13-JUN-12 1 9 528880 13-JUN-12 529115 13-JUN-12 1 10 529115 13-JUN-12 529117 13-JUN-12 1 11 529117 13-JUN-12 529120 13-JUN-12 1 12 529120 13-JUN-12 529129 13-JUN-12 1 13 529129 13-JUN-12 529131 13-JUN-12 1 14 529131 13-JUN-12 529134 13-JUN-12 1 15 529134 13-JUN-12 529136 13-JUN-12 1 16 529136 13-JUN-12 529138 13-JUN-12 1 17 529138 13-JUN-12 529140 13-JUN-12 1 18 529140 13-JUN-12 529142 13-JUN-12 1 19 529142 13-JUN-12 529144 13-JUN-12 1 20 529144 13-JUN-12 529154 13-JUN-12 1 21 529154 13-JUN-12 529156 13-JUN-12 1 22 529156 13-JUN-12 529158 13-JUN-12 1 23 529158 13-JUN-12 529160 13-JUN-12 1 24 529160 13-JUN-12 529162 13-JUN-12 1 25 529162 13-JUN-12 529164 13-JUN-12 1 26 529164 13-JUN-12 529431 13-JUN-12 1 27 529431 13-JUN-12 529433 13-JUN-12 1 28 529433 13-JUN-12 529436 13-JUN-12 1 29 529436 13-JUN-12 529438 13-JUN-12 1 30 529438 13-JUN-12 529440 13-JUN-12 1 31 529440 13-JUN-12 529442 13-JUN-12 1 32 529442 13-JUN-12 529444 13-JUN-12 1 33 529444 13-JUN-12 529446 13-JUN-12 1 34 529446 13-JUN-12 529448 13-JUN-12 1 35 529448 13-JUN-12 529450 13-JUN-12 1 36 529450 13-JUN-12 529452 13-JUN-12 1 37 529452 13-JUN-12 529454 13-JUN-12 1 38 529454 13-JUN-12 529456 13-JUN-12 1 39 529456 13-JUN-12 529458 13-JUN-12 1 40 529458 13-JUN-12 529460 13-JUN-12 1 41 529460 13-JUN-12 529462 13-JUN-12 1 42 529462 13-JUN-12 529464 13-JUN-12 1 43 529464 13-JUN-12 529466 13-JUN-12 1 44 529466 13-JUN-12 529468 13-JUN-12 1 45 529468 13-JUN-12 529470 13-JUN-12 1 46 529470 13-JUN-12 534645 13-JUN-12 1 47 534645 13-JUN-12 539056 13-JUN-12 1 48 539056 13-JUN-12 543505 13-JUN-12 1 49 543505 13-JUN-12 547897 13-JUN-12 1 50 547897 13-JUN-12 552310 13-JUN-12 1 51 552310 13-JUN-12 556688 13-JUN-12 1 52 556688 13-JUN-12 561084 13-JUN-12 1 53 561084 13-JUN-12 565473 13-JUN-12 1 54 565473 13-JUN-12 569854 13-JUN-12 1 55 569854 13-JUN-12 574302 13-JUN-12 1 56 574302 13-JUN-12 579860 13-JUN-12 1 57 579860 13-JUN-12 586089 13-JUN-12 1 58 586089 13-JUN-12 592233 13-JUN-12 1 59 592233 13-JUN-12 598391 13-JUN-12 1 60 598391 13-JUN-12 604553 13-JUN-12 1 61 604553 13-JUN-12 610704 13-JUN-12 1 62 610704 13-JUN-12 616840 13-JUN-12 1 63 616840 13-JUN-12 623696 13-JUN-12 1 64 623696 13-JUN-12 631159 13-JUN-12 1 65 631159 13-JUN-12 637993 13-JUN-12 1 66 637993 13-JUN-12 644418 13-JUN-12 1 67 644418 13-JUN-12 650775 13-JUN-12 1 68 650775 13-JUN-12 659810 13-JUN-12 1 69 659810 13-JUN-12 677285 13-JUN-12 BS Key Type LV Size Device Type Elapsed Time Completion Time ------- ---- -- ---------- ----------- ------------ --------------- 5 Full 7.08M DISK 00:00:03 13-JUN-12 BP Key: 5 Status: AVAILABLE Compressed: NO Tag: TAG20120613T143358 Piece Name: /home/oracle/DiskBackupLocation/c-1762320829-20120613-01 Control File Included: Ckp SCN: 679052 Ckp time: 13-JUN-12 SPFILE Included: Modification time: 13-JUN-12
可以看出上面紅色部分BP Key 5是備份集中最新控制文件的存放位置，我們記住這個目錄，稍後恢復控制文件時要使用。
查看控制文件
SQL> select '!rm '||name from v$controlfile; '!RM '||NAME ------------------------------------------------------------------------------- !rm /u01/app/oracle/oradata/DG1/control01.ctl !rm /u01/app/oracle/oradata/DG1/control02.ctl !rm /u01/app/oracle/oradata/DG1/control03.ctl
將控制文件全部刪除
SQL> !rm /u01/app/oracle/oradata/DG1/control01.ctl !rm /u01/app/oracle/oradata/DG1/control02.ctl !rm /u01/app/oracle/oradata/DG1/control03.ctl
查看控制文件是否還存在
SQL> !ls /u01/app/oracle/oradata/DG1 redo01_a.log redo02.log sysaux01.dbf undotbs01.dbf redo01.log redo03_a.log system01.dbf users01.dbf redo02_a.log redo03.log temp01.dbf
將數據庫關閉，然後重新啓動
SQL> shutdown immediate; ORA-00210: cannot open the specified control file ORA-00202: control file: '/u01/app/oracle/oradata/DG1/control01.ctl' ORA-27041: unable to open file Linux Error: 2: No such file or directory Additional information: 3
竟然正常關閉不了（之前做測試都能正常關閉），直接強制關閉
SQL> shutdown abort; ORACLE instance shut down.
重新啓動數據庫
SQL> startup ORACLE instance started. Total System Global Area 285212672 bytes Fixed Size 1218992 bytes Variable Size 88082000 bytes Database Buffers 192937984 bytes Redo Buffers 2973696 bytes ORA-00205: error in identifying control file, check alert log for more info
出現報錯信息，不能識別控制文件，這是肯定的，由於缺少控制文件，數據庫在由nomount狀態啓動到mount狀態時要讀取控制文件中的內容，控制文件都木有了，怎麼能啓動到mount，還別說open了，所以在數據庫只能啓動到nomount狀態。由於我們有歸檔模式下的RMAN全備，所以我們可以藉助RMAN備份集來恢復參數文件。
SQL> select status from v$instance; STATUS ------------ STARTED
進入RMAN模式
[oracle@DG1 ~]$ rman target sys/oracle@DG1 Recovery Manager: Release 10.2.0.1.0 - Production on Wed Jun 13 22:01:19 2012 Copyright (c) 1982, 2005, Oracle. All rights reserved. connected to target database: DG1 (not mounted)
現在從RMAN完備數據庫的備份集中進行控制文件的恢復
RMAN> restore controlfile from '/home/oracle/DiskBackupLocation/c-1762320829-20120613-01'; Starting restore at 13-JUN-12 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: sid=155 devtype=DISK channel ORA_DISK_1: restoring control file channel ORA_DISK_1: restore complete, elapsed time: 00:00:06 output filename=/u01/app/oracle/oradata/DG1/control01.ctl output filename=/u01/app/oracle/oradata/DG1/control02.ctl output filename=/u01/app/oracle/oradata/DG1/control03.ctl Finished restore at 13-JUN-12
可以看到控制文件已經由全備份集中的控制文件成功恢復
恢復控制完畢，查看控制文件
[oracle@DG1 ~]$ ls /u01/app/oracle/oradata/DG1/ control01.ctl redo01_a.log redo02.log sysaux01.dbf undotbs01.dbf control02.ctl redo01.log redo03_a.log system01.dbf users01.dbf control03.ctl redo02_a.log redo03.log temp01.dbf
將數據庫啓動到mount狀態恢復數據庫
RMAN> alter database mount; database mounted released channel: ORA_DISK_1
成功啓動到mount狀態
執行RMAN恢復數據庫的操作
RMAN> recover database; Starting recover at 13-JUN-12 Starting implicit crosscheck backup at 13-JUN-12 allocated channel: ORA_DISK_1 channel ORA_DISK_1: sid=155 devtype=DISK Crosschecked 3 objects Finished implicit crosscheck backup at 13-JUN-12 Starting implicit crosscheck copy at 13-JUN-12 using channel ORA_DISK_1 Finished implicit crosscheck copy at 13-JUN-12 searching for all files in the recovery area cataloging files... no files cataloged using channel ORA_DISK_1 starting media recovery archive log thread 1 sequence 70 is already on disk as file /u01/app/oracle/oradata/DG1/redo03.log archive log thread 1 sequence 71 is already on disk as file /u01/app/oracle/oradata/DG1/redo01.log archive log filename=/u01/app/oracle/oradata/DG1/redo03.log thread=1 sequence=70 archive log filename=/u01/app/oracle/oradata/DG1/redo01.log thread=1 sequence=71 media recovery complete, elapsed time: 00:00:01 Finished recover at 13-JUN-12
數據庫恢復成功
打開數據庫
RMAN> alter database open resetlogs; database opened RMAN>
成功恢復
由於數據庫一直處於歸檔模式，所以從歸檔下的完備份集恢復數據庫，可以保證數據不丟失，當由備份集恢復控制文件之後，接着會從數據庫的歸檔日誌和undo日誌文件中讀取SCN信息，將恢復的控制文件更新到最新狀態。
五、總結
沒有不丟失數據的數據庫，所以經常備份數據，是很有必要的，也許某一天數據庫就掛掉了，如果有備份，恢復當然容易，如果沒有，也許結果就不一樣了………無論你的數據庫是以何種方式恢復的，一定切記恢復後，做一次歸檔下的全備，這樣就可以儘可能降低恢復數據庫後數據庫再次掛掉後丟失數據的可能性。
原文來自：http://blog.sina.com.cn/s/blog_70e5638f01016s8b.html