My Oracle Support Banner

Corrupt Data Found During RMAN Backup (Doc ID 1610350.1)

Last updated on MARCH 20, 2019

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.3 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Information in this document applies to any platform.
ksfdrfms:Mirror Read file=+DATA/wind/datafile/sysaux.257.797856311 fob=0x3cb15a548 bufp=0x7f1f74501000 blkno=513 nbytes=8192
ksfdrfms: Read success from mirror side=1 logical extent number=0 disk=DATA_0002 path=/dev/asmdisks/oracle_ocr02p1

Symptoms

11.2.0.3 using ASM.

During RMAN backup, the following messages are generated on alert.log:

Data in bad block:
type: 1 format: 2 rdba: 0x00003156
last change scn: 0xb408.00000003 seq: 0x8 flg: 0x01
spare1: 0x8 spare2: 0x1 spare3: 0x0
consistency value in tail: 0x00000000
check value in block header: 0x9
block checksum disabled
Trying mirror side DATA_0002.
Reread of blocknum=555, file=+<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311. found same corrupt data
Reread of blocknum=393, file=+<diskgroup>/<db_unique_name>/datafile/undotbs2.267.797856405. found valid data
Reread of blocknum=555, file=+<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311. found valid data
Hex dump of (file 5, block 394) in trace file /<path>/trace/<oracle_sid>_ora_1825.trc
Corrupt block relative dba: 0x0140018a (file 5, block 394)
Bad header found during backing up datafileHex dump of (file 2, block 556) in trace file /<path>/trace/<oracle_sid>_ora_1826.trc

- Trace file <oracle_sid>_ora_31631.trc shows the blocks can be read from mirror:

Corrupt block relative dba: 0x00800201 (file 2, block 513)
Bad header found during backing up datafile
Data in bad block:
 type: 1 format: 2 rdba: 0x00003102
 last change scn: 0xb408.00000003 seq: 0x8 flg: 0x01
 spare1: 0x8 spare2: 0x1 spare3: 0x0
 consistency value in tail: 0x00000000
 check value in block header: 0x9
 block checksum disabled
ksfdrfms:Mirror Read file=+<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311 fob=0x3cb15a548 bufp=0x7f1f74501000 blkno=513 nbytes=8192
ksfdrfms: Read success from mirror side=1 logical extent number=0 disk=DATA_0002 path=/<disk_path>
Mirror I/O done from ASM disk /<disk_path>
Trying mirror side DATA_0002.
Reread of blocknum=513, file=+<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311. found same corrupt data
ksfdrnms:Mirror Read file=+<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311 fob=0x3cb15a548 bufp=0x7f1f74501000 nbytes=8192
ksfdrnms: Read success from mirror side=2 logical extent number=1 disk=DATA_0003 path=/<disk_path>
Mirror I/O done from ASM disk /<disk_path> 
Reread of blocknum=513, file=+<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311. found valid data

- The back runs to completion based on mirror blocks, but the datafiles remain with corruptions:

DBVERIFY - Verification starting : FILE = +<diskgroup>/<db_unique_name>/datafile/sysaux.257.797856311
...
Total Pages Marked Corrupt : 128

_ RMAN doesn't report any corrupted blocks reading the good copy from the mirror.

Customer needs to fix the mirror.

Cause

To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!


In this Document
Symptoms
Cause
Solution
References


My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.