資料庫壞塊解決案例一則

收到開發人員報告，oracle出現壞塊，檢視alert.log，資訊如下：
Hex dump of (file 7, block 1407500) in trace file /data/oracle/admin/orcl/bdump/orcl_p004_7383.trc
Corrupt block relative dba: 0x01d57a0c (file 7, block 1407500)
Fractured block found during crash/instance recovery
Data in bad block:
type: 6 format: 2 rdba: 0x01d57a0c
last change scn: 0x0000.e02e5f2d seq: 0x1 flg: 0x06
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x88150601
check value in block header: 0x462f
computed block checksum: 0xd738
Reread of rdba: 0x01d57a0c (file 7, block 1407500) found same corrupted data



解決思路：

首先確認該壞塊所屬物件，發現為索引，名字為IDX_D_D_PRODUCT_ID
確認該壞塊屬於索引IDX_D_D_PRODUCT_ID。先重建索引暫時解決問題：
SQL> alter index IDX_D_D_PRODUCT_ID rebuild online tablespace pur_index ;

Index altered.
注：必須加上online關鍵字，一則因為是線上環境，二則不加Online會在原索引基礎上重建，不會解決問題，即加上關鍵字online, 重建後的索引會從表裡取資料

使用dbv檢查：
[oracle@rac1 ~]$ dbv file=/data/oracle/oradata/orcl/justin03.dbf blocksize=8192

DBVERIFY: Release 10.2.0.1.0 - Production on Thu Jul 29 10:53:48 2010

Copyright (c) 1982, 2005, Oracle. All rights reserved.

DBVERIFY - Verification starting : FILE = /data/oracle/oradata/orcl/justin03.dbf

DBV-00200: Block, dba 30767628, already marked corrupted

DBVERIFY - Verification complete

Total Pages Examined : 4194302
Total Pages Processed (Data) : 3508146
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 605887
Total Pages Failing (Index): 0
Total Pages Processed (Other): 75876
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 4393
Total Pages Marked Corrupt : 1
Total Pages Influx : 0
Highest block SCN : 3781089739 (0.3781089739)

我們也可以使用如下過程確定壞塊屬於哪個block:

SQL> select dbms_utility.data_block_address_file(30767628) from dual;

DBMS_UTILITY.DATA_BLOCK_ADDRESS_FILE(30767628)



--------------------------------------------------------------------------------

7

Elapsed: 00:00:00.23
SQL> select dbms_utility.data_block_address_block(30767628) from dual;

DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(30767628)



--------------------------------------------------------------------------------

1407500



其次要確認壞塊型別是物理壞塊還是邏輯壞塊
physical corruption check: backup validate datafile 'filename';
logical corruption check: backup check logical validate datafile 'filename'

先進行物理壞塊檢測
RMAN> backup validate datafile 7;

Starting backup at 29-JUL-10
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=1736 devtype=DISK
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00007 name=/data/oracle/oradata/orcl/justin03.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:35
Finished backup at 29-JUL-10

sys@std01> select * from V$DATABASE_BLOCK_CORRUPTION;

FILE# BLOCK# BLOCKS CORRUPTION_CHANGE# CORRUPTIO



--------------------------------------------------------------------------------
---------- ---------- ------------------ ---------
7 1407500 1 0 CORRUPT

確認為物理壞塊

最後也是最重要的一步，進行壞塊恢復，
RMAN> BLOCKRECOVER CORRUPTION LIST；

Starting blockrecover at 29-JUL-10
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=455 devtype=DISK

channel ORA_DISK_1: restoring block(s)
channel ORA_DISK_1: specifying block(s) to restore from backup set
restoring blocks of datafile 00007
channel ORA_DISK_1: reading from backup piece /backup/rman/rac1_ORCL_20100729_eoljvn41_1_1.bak


channel ORA_DISK_1: restored block(s) from backup piece 1
piece handle=/backup/rman/rac1_ORCL_20100729_eoljvn41_1_1.bak tag=TAG20100729T050504
channel ORA_DISK_1: block restore complete, elapsed time: 00:57:56
failover to previous backup

channel ORA_DISK_1: restoring block(s)
channel ORA_DISK_1: specifying block(s) to restore from backup set
restoring blocks of datafile 00007
channel ORA_DISK_1: reading from backup piece /backup/rman/rac1_ORCL_20100728_eiljt2ju_1_1.bak


channel ORA_DISK_1: restored block(s) from backup piece 1
piece handle=/backup/rman/rac1_ORCL_20100728_eiljt2ju_1_1.bak tag=TAG20100728T050253
channel ORA_DISK_1: block restore complete, elapsed time: 00:58:36

starting media recovery

media recovery complete, elapsed time: 00:12:15

Finished blockrecover at 29-JUL-10

命令完成，分別使用DBV和backup validate命令進行驗證
[oracle@rac1 ~]$ dbv file=/data/oracle/oradata/orcl/justin03.dbf blocksize=8192

DBVERIFY: Release 10.2.0.1.0 - Production on Thu Jul 29 19:04:45 2010

Copyright (c) 1982, 2005, Oracle. All rights reserved.

DBVERIFY - Verification starting : FILE = /data/oracle/oradata/orcl/justin03.dbf


DBVERIFY - Verification complete

Total Pages Examined : 4194302
Total Pages Processed (Data) : 3507791
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 606239
Total Pages Failing (Index): 0
Total Pages Processed (Other): 75879
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 4393
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Highest block SCN : 3785553739 (0.3785553739)

使用 backup validate datafile 進行驗證：
驗證前：
SQL> select * from V$DATABASE_BLOCK_CORRUPTION;

FILE# BLOCK# BLOCKS CORRUPTION_CHANGE# CORRUPTIO



--------------------------------------------------------------------------------
---------- ---------- ------------------ ---------
7 1407500 1 0 CORRUPT

[oracle@rac1 ~]$ rman target /

Recovery Manager: Release 10.2.0.1.0 - Production on Thu Jul 29 21:17:10 2010

Copyright (c) 1982, 2005, Oracle. All rights reserved.

connected to target database: ORCL (DBID=1185342296)

RMAN> backup validate datafile 7;

Starting backup at 29-JUL-10
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=455 devtype=DISK
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00007 name=/data/oracle/oradata/orcl/justin03.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:02:35
Finished backup at 29-JUL-10

執行完上述命令，壞塊從資料字典裡消失：
SQL> select * from V$DATABASE_BLOCK_CORRUPTION;
no rows selected

問題得到解決。

[ 本帖最後由 myownstars 於 2010-12-15 15:43 編輯 ]