rman還原控制檔案（一）

如果丟失或損壞所有的控制檔案就需要從備份中還原控制檔案。restore controlfile命令用來還原控制檔案。在還原控制檔案後需要對資料畝執行完全介質恢復並以resetlog選項來開啟資料庫。RMAN可以將控制檔案還原到它的預設儲存位置，也可以使用restore controlfile ... to destination來指定位置。

從已經知的控制檔案備份中還原控制檔案

SQL> show parameter control_files

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
control_files                        string      /u01/app/oracle/oradata/test/c
                                                 ontrol01.ctl, /u01/app/oracle/
                                                 oradata/test/control02.ctl, /u
                                                 01/app/oracle/oradata/test/con
                                                 trol03.ctl

顯示當前可用的備份

RMAN> list backup;


List of Backup Sets
===================

BS Key  Size       Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
77      693.50K    DISK        00:00:02     28-JAN-15
        BP Key: 75   Status: AVAILABLE  Compressed: YES  Tag: TAG20150128T131713
        Piece Name: /u02/test_df870182233_s95_s1

  List of Archived Logs in backup set 77
  Thrd Seq     Low SCN    Low Time  Next SCN   Next Time
  ---- ------- ---------- --------- ---------- ---------
  1    13      2928236    28-JAN-15 2928830    28-JAN-15

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
78      Full    166.91M    DISK        00:01:19     28-JAN-15
        BP Key: 76   Status: AVAILABLE  Compressed: YES  Tag: TAG20150128T131716
        Piece Name: /u02/test_df870182236_s96_s1
  List of Datafiles in backup set 78
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  1       Full 2928835    28-JAN-15 /u01/app/oracle/oradata/test/system01.dbf
  2       Full 2928835    28-JAN-15 /u01/app/oracle/oradata/test/undotbs01.dbf
  3       Full 2928835    28-JAN-15 /u01/app/oracle/oradata/test/sysaux01.dbf
  4       Full 2928835    28-JAN-15 /u01/app/oracle/oradata/test/users01.dbf
  5       Full 2928835    28-JAN-15 /u01/app/oracle/oradata/test/example01.dbf
  6       Full 2928835    28-JAN-15 /u01/app/oracle/oradata/test/test01.dbf

BS Key  Size       Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
79      7.50K      DISK        00:00:01     28-JAN-15
        BP Key: 77   Status: AVAILABLE  Compressed: YES  Tag: TAG20150128T131841
        Piece Name: /u02/test_df870182321_s97_s1

  List of Archived Logs in backup set 79
  Thrd Seq     Low SCN    Low Time  Next SCN   Next Time
  ---- ------- ---------- --------- ---------- ---------
  1    14      2928830    28-JAN-15 2928868    28-JAN-15

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
80      Full    9.42M      DISK        00:00:02     28-JAN-15
        BP Key: 78   Status: AVAILABLE  Compressed: NO  Tag: TAG20150128T131843
        Piece Name: /u01/app/oracle/10.2.0/db/dbs/c-2155613261-20150128-0d
  Control File Included: Ckp SCN: 2928874      Ckp time: 28-JAN-15
  SPFILE Included: Modification time: 28-JAN-15

從上面的資訊可以看到備份集80是控制檔案與spfile檔案的備份

下面來刪除當前資料庫的所有控制檔案：

[root@oracle11g ~]# cd /u01/app/oracle/oradata/test/
[root@oracle11g test]# ls -lrt
total 2213868
-rw-r----- 1 oracle oinstall  11804672 Feb  1 11:36 users01.dbf
-rw-r----- 1 oracle oinstall  52436992 Feb  1 11:36 test01.dbf
-rw-r----- 1 oracle oinstall  52429312 Feb  1 11:36 redo02.log
-rw-r----- 1 oracle oinstall  52429312 Feb  1 11:36 redo01.log
-rw-r----- 1 oracle oinstall 104865792 Feb  1 11:36 example01.dbf
-rw-r----- 1 oracle oinstall  20979712 Feb  1 11:37 temp01.dbf
-rw-r----- 1 oracle oinstall 838868992 Feb  1 19:05 system01.dbf
-rw-r----- 1 oracle oinstall 492838912 Feb  1 19:05 undotbs01.dbf
-rw-r----- 1 oracle oinstall 576724992 Feb  1 19:05 sysaux01.dbf
-rw-r----- 1 oracle oinstall  52429312 Feb  1 19:10 redo03.log
-rw-r----- 1 oracle oinstall   9814016 Feb  1 19:11 control03.ctl
-rw-r----- 1 oracle oinstall   9814016 Feb  1 19:11 control02.ctl
-rw-r----- 1 oracle oinstall   9814016 Feb  1 19:11 control01.ctl
[root@oracle11g test]# rm -rf control*.ctl
[root@oracle11g test]# ls -lrt
total 2185068
-rw-r----- 1 oracle oinstall  52429312 Feb  1 11:36 redo02.log
-rw-r----- 1 oracle oinstall  20979712 Feb  1 11:37 temp01.dbf
-rw-r----- 1 oracle oinstall  52429312 Feb  1 19:13 redo03.log
-rw-r----- 1 oracle oinstall  11804672 Feb  1 19:14 users01.dbf
-rw-r----- 1 oracle oinstall 492838912 Feb  1 19:14 undotbs01.dbf
-rw-r----- 1 oracle oinstall  52436992 Feb  1 19:14 test01.dbf
-rw-r----- 1 oracle oinstall 838868992 Feb  1 19:14 system01.dbf
-rw-r----- 1 oracle oinstall 576724992 Feb  1 19:14 sysaux01.dbf
-rw-r----- 1 oracle oinstall  52429312 Feb  1 19:14 redo01.log
-rw-r----- 1 oracle oinstall 104865792 Feb  1 19:14 example01.dbf

向測試表t2中插入一些資料庫

SQL> insert into t2 select * from dba_objects;

51319 rows created.

SQL> select count(*) from t2;

  COUNT(*)
----------
    102560

SQL> commit;

Commit complete.

這裡因為是從linux作業系統層面刪除了所有控制檔案，因為在資料庫沒有關閉的情況下檔案的控制程式碼沒有釋放所以資料庫還能執行。

人為將資料庫異常終止

[root@oracle11g test]# ps -ef | grep smon
oracle    3463     1  0 22:30 ?        00:00:00 ora_smon_test
root      3179  3123  0 22:45 pts/3    00:00:00 grep smon
[root@oracle11g test]# kill -9 3463

啟動資料庫：

SQL> startup
ORACLE instance started.

Total System Global Area  327155712 bytes
Fixed Size                  1273516 bytes
Variable Size             138412372 bytes
Database Buffers          184549376 bytes
Redo Buffers                2920448 bytes
ORA-00205: error in identifying control file, check alert log for more info

alert日誌的內容如下:

ORA-00210: cannot open the specified control file
ORA-00202: control file: '/u01/app/oracle/oradata/test/control01.ctl'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Sun Feb 01 19:18:18 CST 2015
ORA-205 signalled during: ALTER DATABASE   MOUNT...

找不到控制檔案不能將資料庫置於mount狀態.現在透過備份來還原控制檔案執行完全資料庫恢復:

RMAN> restore controlfile from '/u01/app/oracle/10.2.0/db/dbs/c-2155613261-20150128-0d';

Starting restore at 01-FEB-15
using channel ORA_DISK_1

channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:05
output filename=/u01/app/oracle/oradata/test/control01.ctl
output filename=/u01/app/oracle/oradata/test/control02.ctl
output filename=/u01/app/oracle/oradata/test/control03.ctl
Finished restore at 01-FEB-15


RMAN> sql 'alter database mount';

sql statement: alter database mount
released channel: ORA_DISK_1

SQL> select status from v$instance;

STATUS
------------------------
MOUNTED

執行完全恢復

RMAN> recover database;

Starting recover at 01-FEB-15
Starting implicit crosscheck backup at 01-FEB-15
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=155 devtype=DISK
Crosschecked 3 objects
Finished implicit crosscheck backup at 01-FEB-15

Starting implicit crosscheck copy at 01-FEB-15
using channel ORA_DISK_1
Crosschecked 6 objects
Finished implicit crosscheck copy at 01-FEB-15

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 17 is already on disk as file /u01/app/oracle/oradata/test/redo02.log
archive log thread 1 sequence 18 is already on disk as file /u01/app/oracle/oradata/test/redo03.log
archive log thread 1 sequence 19 is already on disk as file /u01/app/oracle/oradata/test/redo01.log
archive log filename=/u02/1_15_870133266.dbf thread=1 sequence=15
archive log filename=/u02/1_16_870133266.dbf thread=1 sequence=16
archive log filename=/u01/app/oracle/oradata/test/redo02.log thread=1 sequence=17
archive log filename=/u01/app/oracle/oradata/test/redo03.log thread=1 sequence=18
archive log filename=/u01/app/oracle/oradata/test/redo01.log thread=1 sequence=19
media recovery complete, elapsed time: 00:00:06
Finished recover at 01-FEB-15


RMAN> sql 'alter database open resetlogs';

sql statement: alter database open resetlogs

SQL>  select status from v$instance;

STATUS
------------
OPEN

SQL> select count(*) from t2;

  COUNT(*)
----------
    102560

表t2中的記錄與恢復之前相同，說明恢復成功。

當還原控制檔案時，控制檔案的預設位置是由引數control_files控制的。如果沒有設定control_files引數，那麼資料庫判斷還原控制檔案儲存位置的規則將會與沒有設定control_files引數時建立控制檔案時使用的規則一樣。