rman恢復資料檔案-----塊折斷

這幾天重新複習了一下rman備份與恢復，感覺要學的東西實在是太多，
模擬了一下實驗，將實驗過程記錄下來，以便日後查閱。


試驗目的

rman功能很強大，10g以後可以通過rman對某個損壞資料檔案的具體塊做恢復。


試驗環境

OS: redhat linuxas4
DB: oracle10g r2

試驗步驟

1：在sxit使用者下建立一個表cc，往表裡插入資料，並提交。

SQL> select count(*) from sxit.cc;
  COUNT(*)
----------
    449480

2：根據 dba_data_files 檢視和 all_tables 檢視檢視sxit使用者下所建立的表cc 屬於哪個資料檔案。

3：以nocatalog方式連線到資料庫中，用rman工具進行資料庫全備

[oracle@catalog ~]$ export PATH=$ORACLE_HOME/binATH:.
[oracle@catalog ~]$ rman target / nocatalog
Recovery Manager: Release 10.2.0.1.0 - Production on Fri Jul 15 17:58:25 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
connected to target database: ORA10HHA (DBID=3339398398)
using target database control file instead of recovery catalog
RMAN> backup database;

備份後，預設就在閃回區生成一個備份集檔案。


4：用 shutdown immediate命令關閉資料庫

5：將sxit使用者下cc表所屬的資料檔案下載到本地xp系統上，並通過 ultraedit 工具編輯 資料檔案users01.dbf 中的內容，模擬資料塊損壞。
注意：不要編輯資料檔案的頭部前八個位元組。（資料庫啟動的時候，會檢查控制檔案和資料檔案頭部，如果不一致資料庫就會打不開）
然後儲存，重新上傳到原始目錄下。

6：再次查詢cc表，發現表無法訪問，並報塊折斷錯誤提示。
SQL> select count(*) from sxit.CC;
select count(*) from sxit.CC
                          *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 1600)
ORA-01110: data file 4: '/home/oracle/oradata/ora10hha/users01.dbf'

7：在作業系統層面驗證資料是否有損壞。

[oracle@catalog ora10hha]$ dbv file='/home/oracle/oradata/ora10hha/users01.dbf'
DBVERIFY: Release 10.2.0.1.0 - Production on Fri Jul 15 17:52:25 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
DBVERIFY - Verification starting : FILE = /home/oracle/oradata/ora10hha/users01.dbf
Page 359 is marked corrupt
Corrupt block relative dba: 0x01000167 (file 4, block 359)
Bad check value found during dbv:
Data in bad block:
type: 6 format: 2 rdba: 0x01000167
last change scn: 0x0000.000ea3fd seq: 0x4c flg: 0x04
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0xa3fd064c
check value in block header: 0x59b1
computed block checksum: 0x7981
Page 1600 is marked corrupt
Corrupt block relative dba: 0x01000640 (file 4, block 1600)
Bad check value found during dbv:
Data in bad block:
type: 6 format: 2 rdba: 0x01000640
last change scn: 0x0000.000ff474 seq: 0x1 flg: 0x04
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0xf4740601
check value in block header: 0xf984
computed block checksum: 0x9871

DBVERIFY - Verification complete
Total Pages Examined         : 16320
Total Pages Processed (Data) : 15470
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 14
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 238
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 596
Total Pages Marked Corrupt   : 2
Total Pages Influx           : 0
Highest block SCN            : 1310735 (0.1310735)
[oracle@catalog ora10hha]$

從執行結果可以看出，第4號資料檔案的第359個塊和第1600個塊有損壞。


也可以從rman中進行資料庫塊是否有損壞

[oracle@catalog ~]$ rman target / nocatalog
Recovery Manager: Release 10.2.0.1.0 - Production on Fri Jul 15 17:58:25 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
connected to target database: ORA10HHA (DBID=3339398398)
using target database control file instead of recovery catalog
RMAN> backup validate database;
Starting backup at 15-JUL-11
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=153 devtype=DISK
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00005 name=/home/oracle/oradata/ora10hha/cata.dbf
input datafile fno=00001 name=/home/oracle/oradata/ora10hha/system01.dbf
input datafile fno=00002 name=/home/oracle/oradata/ora10hha/undotbs01.dbf
input datafile fno=00003 name=/home/oracle/oradata/ora10hha/sysaux01.dbf
input datafile fno=00004 name=/home/oracle/oradata/ora10hha/users01.dbf
input datafile fno=00006 name=/home/oracle/oradata/ora10hha/tz.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:02:16
Finished backup at 15-JUL-11

然後在以下檢視中有記錄：

select * from v$database_block_corruption
結果見附件中。


8：用rman恢復對應的資料塊。

如果不用rman備份資料檔案的話，那麼在恢復資料的時候，就需要將這個資料檔案全部拷貝過去，然後進行
恢復。如果碰到上百個G的大資料檔案，為了幾個損壞的塊進行恢復需要耗費很久的時間。
但是如果使用rman工具，就可以對單個的資料檔案塊進行恢復，很方便。

[oracle@catalog ~]$ rman target / nocatalog
Recovery Manager: Release 10.2.0.1.0 - Production on Fri Jul 15 17:58:25 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
connected to target database: ORA10HHA (DBID=3339398398)
using target database control file instead of recovery catalog

RMAN> blockrecover datafile 4 block 359;
Starting blockrecover at 15-JUL-11
using channel ORA_DISK_1
channel ORA_DISK_1: restoring block(s)
channel ORA_DISK_1: specifying block(s) to restore from backup set
restoring blocks of datafile 00004
channel ORA_DISK_1: reading from backup piece /home/oracle/flash_recovery_area/ORA10HHA/backupset/2011_07_15/o1_mf_nnndf_TAG20110715T163759_71zz37r4_.bkp
channel ORA_DISK_1: restored block(s) from backup piece 1
piece handle=/home/oracle/flash_recovery_area/ORA10HHA/backupset/2011_07_15/o1_mf_nnndf_TAG20110715T163759_71zz37r4_.bkp tag=TAG20110715T163759
channel ORA_DISK_1: block restore complete, elapsed time: 00:00:27
starting media recovery
media recovery complete, elapsed time: 00:00:04
Finished blockrecover at 15-JUL-11
RMAN> blockrecover datafile 4 block 1600;
Starting blockrecover at 15-JUL-11
using channel ORA_DISK_1
channel ORA_DISK_1: restoring block(s)
channel ORA_DISK_1: specifying block(s) to restore from backup set
restoring blocks of datafile 00004
channel ORA_DISK_1: reading from backup piece /home/oracle/flash_recovery_area/ORA10HHA/backupset/2011_07_15/o1_mf_nnndf_TAG20110715T163759_71zz37r4_.bkp
channel ORA_DISK_1: restored block(s) from backup piece 1
piece handle=/home/oracle/flash_recovery_area/ORA10HHA/backupset/2011_07_15/o1_mf_nnndf_TAG20110715T163759_71zz37r4_.bkp tag=TAG20110715T163759
channel ORA_DISK_1: block restore complete, elapsed time: 00:00:35
starting media recovery
media recovery complete, elapsed time: 00:00:04
Finished blockrecover at 15-JUL-11
RMAN>

9：恢復以後，然後檢視cc表，可以訪問。


SQL> select count(*) from sxit.cc;
  COUNT(*)
----------
    449480
SQL>

rman.jpg

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