--模拟controlfile丢失与重建
----------------------------------------------------------------2013/09/21
1. 关闭数据库。
2. 将controlfile重命名模拟丢失。
[Oracle@localhost august]$ mv control01.ctl control01.ctl_bkp
[Oracle@localhost august]$ mv control02.ctl control02.ctl_bkp
3. 使用rman启动数据库。
RMAN> startup mount;
Oracle instance started
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of startup command at 09/20/2013 20:03:34
ORA-00205: error in identifying control file, check alert log for more info
没有control file只能启动到nomount状态。
4. 即使没有控制文件，RMAN还是能识别自己的autobackup目录，可以直接使用下面命令
RMAN> restore controlfile to '/u01/app/oracle/oradata/august/august/control01.ctl' from autobackup;
我们可以也通过直接指定自动备份集来进行恢复。
RMAN> restore controlfile to '/u01/app/oracle/oradata/august/august/control01.ctl' from '/u01/app/oracle/flash_recovery_area/august/AUGUST/autobackup/2013_09_20/o1_mf_s_826618674_93rss9os_.bkp';
Starting restore at 20-SEP-13
using channel ORA_DISK_1
channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
Finished restore at 20-SEP-13
启动数据库到mount
RMAN> alter database mount;
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of alter db command at 09/20/2013 20:22:24
ORA-00205: error in identifying control file, check alert log for more info
--因为ORACLE这里要求所有的控制的文件都要被一致的恢复，在此数据库中有两份控制文件，我们这里只恢复了一份，它不能识别。这些信息在参数文件中指定好了。
RMAN> restore controlfile to '/u01/app/oracle/flash_recovery_area/august/august/control02.ctl' from autobackup;
Starting restore at 20-SEP-13
using channel ORA_DISK_1
recovery area destination: /u01/app/oracle/flash_recovery_area/august
database name (or database unique name) used for search: AUGUST
channel ORA_DISK_1: AUTOBACKUP /u01/app/oracle/flash_recovery_area/august/AUGUST/autobackup/2013_09_20/o1_mf_s_826618674_93rss9os_.bkp found in the recovery area
channel ORA_DISK_1: looking for AUTOBACKUP on day: 20130920
channel ORA_DISK_1: restoring control file from AUTOBACKUP /u01/app/oracle/flash_recovery_area/august/AUGUST/autobackup/2013_09_20/o1_mf_s_826618674_93rss9os_.bkp
channel ORA_DISK_1: control file restore from AUTOBACKUP complete
Finished restore at 20-SEP-13
RMAN> alter database mount;
database mounted
released channel: ORA_DISK_1
恢复另一份控制文件后，就可以正常mount了。
或者我们可以直接采用下面这种方式，ORACLE自己决定恢复的目录。
RMAN> restore controlfile from '/u01/app/oracle/flash_recovery_area/august/AUGUST/autobackup/2013_09_20/o1_mf_s_826618674_93rss9os_.bkp';
Starting restore at 20-SEP-13
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:15
output file name=/u01/app/oracle/oradata/august/august/control01.ctl
output file name=/u01/app/oracle/flash_recovery_area/august/august/control02.ctl
Finished restore at 20-SEP-13
RMAN> alter database mount;
database mounted
released channel: ORA_DISK_1
由于控制文件恢复，进行数据库恢复，同步文件信息。
RMAN> recover database;
Starting recover at 20-SEP-13
Starting implicit crosscheck backup at 20-SEP-13
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
Crosschecked 3 objects
Finished implicit crosscheck backup at 20-SEP-13
Starting implicit crosscheck copy at 20-SEP-13
using channel ORA_DISK_1
Finished implicit crosscheck copy at 20-SEP-13
searching for all files in the recovery area
cataloging files...
cataloging done
List of Cataloged Files
=======================
File Name: /u01/app/oracle/flash_recovery_area/august/AUGUST/autobackup/2013_09_20/o1_mf_s_826618674_93rss9os_.bkp
using channel ORA_DISK_1
/*完成更新同步控制文件中的备份信息*/
starting media recovery
archived log for thread 1 with sequence 1 is already on disk as file /u01/app/oracle/oradata/august/august/redo01.log
archived log file name=/u01/app/oracle/oradata/august/august/redo01.log thread=1 sequence=1
media recovery complete, elapsed time: 00:00:09
Finished recover at 20-SEP-13
/*完成介质恢复*/
--转储数据文件头文件
SQL> alter session set events 'immediate trace name file_hdrs level 10';
*** 2013-09-20 21:06:30.810
DUMP OF DATA FILES: 4 files in database
DATA FILE #1:
name #7: /u01/app/oracle/oradata/august/august/system01.dbf
creation size=0 block size=8192 status=0xe head=7 tail=7 dup=1
tablespace 0, index=1 krfil=1 prev_file=0
unrecoverable scn: 0x0000.00000000 01/01/1988 00:00:00
Checkpoint cnt:105 scn: 0x0000.000d0471 09/20/2013 19:59:32 /*853105 : <1> 845017 --2.8147E+14 1号日志文件*/
Stop scn: 0x0000.000d0471 09/20/2013 19:59:32
--转储新的控制信息
-DATABASE
Database checkpoint: Thread=1 scn: 0x0000.000ce4dc /*847180*/
-CHECKPOINT
low cache rba:(0x1.3.0) on disk rba:(0x1.72.0)
on disk scn: 0x0000.000ce57a 09/20/2013 08:17:51 /*845178*/ /*检查点都没有得到更新，数据库还没打开也可以理解*/
-DATAFILE
Checkpoint cnt:105 scn: 0x0000.000d0471 09/20/2013 19:59:32
Stop scn: 0x0000.000d0471 09/20/2013 19:59:32 /*datafile的信息都同步为最新*/
--打开数据库
RMAN> alter database open;
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of alter db command at 09/20/2013 20:59:08
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open
RMAN> alter database open noresetlogs;
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "identifier": expecting one of: "resetlogs, ;"
RMAN-01008: the bad identifier was: noresetlogs
RMAN-01007: at line 1 column 21 file: standard input
--可见即使信息同步了，我们也只能以resetlogs方式打开数据库。这里需要指出常见的几种情况，需要以resetlogs方式打开数据库。
1. 在执行了不完全恢复之后。
2. 在使用了备份的控制文件进行恢复后。
3. 使用带有resetlogs选项创建的控制文件恢复之后。
RMAN> alter database open resetlogs;
database opened