bbed处理一个坏块的过程

在备份过程中遇到一个坏块，报错如下：

RMAN> backup database format='/home/ora10g/backup/dbfull_%U.bak';

Starting backup at 2013-09-14

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=147 devtype=DISK

channel ORA_DISK_1: starting full datafile backupset

channel ORA_DISK_1: specifying datafile(s) in backupset

input datafile fno=00001 name=/opt/oracle/oradata/ORCL/system01.dbf

input datafile fno=00003 name=/opt/oracle/oradata/ORCL/sysaux01.dbf

input datafile fno=00005 name=/opt/oracle/oradata/ORCL/test01.dbf

input datafile fno=00002 name=/opt/oracle/oradata/ORCL/undotbs01.dbf

input datafile fno=00004 name=/opt/oracle/oradata/ORCL/users01.dbf

channel ORA_DISK_1: starting piece 1 at 2013-09-14

RMAN-03009: failure of backup command on ORA_DISK_1 channel at 09/14/2013 21:04:45

ORA-19566: exceeded limit of 0 corrupt blocks for file /opt/oracle/oradata/ORCL/test01.dbf

continuing other job steps, job failed will not be re-run

channel ORA_DISK_1: starting full datafile backupset

channel ORA_DISK_1: specifying datafile(s) in backupset

including current control file in backupset

including current SPFILE in backupset

channel ORA_DISK_1: starting piece 1 at 2013-09-14

channel ORA_DISK_1: finished piece 1 at 2013-09-14

piece handle=/home/ora10g/backup/dbfull_02ojrvfd_1_1.bak tag=TAG20130914T210441 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:05

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03009: failure of backup command on ORA_DISK_1 channel at 09/14/2013 21:04:45

ORA-19566: exceeded limit of 0 corrupt blocks for file /opt/oracle/oradata/ORCL/test01.dbf

Hex dump of (file 5, block 22) in trace file /opt/oracle/admin/ORCL/udump/orcl_ora_8007.trc

Corrupt block relative dba: 0x01400016 (file 5, block 22) --可以看到坏块是file 5 block 22

Fractured block found during backing up datafile

Data in bad block:

type: 6 format: 2 rdba: 0x01400016

last change scn: 0x0000.00000000 seq: 0x2 flg: 0x04

spare1: 0x0 spare2: 0x0 spare3: 0x0

consistency value in tail: 0x000006ff

check value in block header: 0xbfa1

computed block checksum: 0x0

从报错信息可以看出是由于tail值和实际的值不一样。

tail应该是scn后四位加type加seq，用bbed修改如下：

BBED> set file 5 block 22

FILE# 5

BLOCK# 22

BBED> verify

DBVERIFY - Verification starting

FILE = /opt/oracle/oradata/ORCL/test01.dbf

BLOCK = 22

Block 22 is corrupt

Corrupt block relative dba: 0x01400016 (file 0, block 22)

Fractured block found during verification

Data in bad block:

type: 6 format: 2 rdba: 0x01400016

last change scn: 0x0000.00000000 seq: 0x2 flg: 0x04

spare1: 0x0 spare2: 0x0 spare3: 0x0

consistency value in tail: 0x000006ff

check value in block header: 0xbfa1

computed block checksum: 0x0

DBVERIFY - Verification complete

Total Blocks Examined : 1

Total Blocks Processed (Data) : 0

Total Blocks Failing (Data) : 0

Total Blocks Processed (Index): 0

Total Blocks Failing (Index): 0

Total Blocks Empty : 0

Total Blocks Marked Corrupt : 1 --被标记为坏块

Total Blocks Influx : 2

BBED> p tailchk

ub4 tailchk @8188 0x000006ff

BBED> modify /x 0206 offset 8188

Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y

File: /opt/oracle/oradata/ORCL/test01.dbf (5)

Block: 22 Offsets: 8188 to 8191 Dba:0x01400016

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

02060000

<32 bytes per line>

BBED> sum apply

Check value for File 5, Block 22:

current = 0xbf5c, required = 0xbf5c

BBED> p tailchk

ub4 tailchk @8188 0x00000602

BBED> verify

DBVERIFY - Verification starting

FILE = /opt/oracle/oradata/ORCL/test01.dbf

BLOCK = 22

DBVERIFY - Verification complete

Total Blocks Examined : 1

Total Blocks Processed (Data) : 1

Total Blocks Failing (Data) : 0

Total Blocks Processed (Index): 0

Total Blocks Failing (Index): 0

Total Blocks Empty : 0

Total Blocks Marked Corrupt : 0 --坏块已消失

Total Blocks Influx : 0