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Oracle Physical Block Corruption

Posted by PDSERVICE on 11月 13, 2015 In

Detected in Block read or proactively detected by Tools (rman,dbv).

Normally reported with error ORA-1578 and the detailed corruption description is printed in the alert log.

This is when the block header cannot be read (Block Header overwritten, Block is incomplete (Fractured=Header/footer mismatch), or checksum errors (block is overwritten), etc.

The corruption is normally permanent and present on Disk with an Invalid or not readable Checksum .

Corruption is not present in the redo log stream. A DATABASE RECOVERY would fix the corruption.

Error – ORA-1578 is produced. Alert log is updated with corruption description for the physical block corruption (Fractured block in this case):

Corrupt block relative dba: 0x02c0002a (file 11, block 42)

Fractured block found during buffer read

Data in bad block -

type: 6 format: 2 rdba: 0x02c0002a

last change scn: 0x0771.4eebe776 seq: 0x2 flg: 0x04

consistency value in tail: 0x77000602 the expected value was 0xe7760602

check value in block header: 0x43b3, computed block checksum: 0x0

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

***

Reread of rdba: 0x02c0002a (file 11, block 42) found same corrupted

data

Physical and Logical Block Corruptions. All you wanted to know about it. (Doc ID 840978.1).

Physical Block Corruption - Causes

Commonly Caused by Hardware / IO problems

OS/Hardware Bugs:

Known Corruption issues caused by 3rd party Software Provider (Doc ID 1323649.1)

Oracle Defect.

Client software overwriting a datafile (Uncommon):

Bug 8943287 ORA-1578 corrupt block with SQL*Net AUTH strings (Doc ID 976852.1)

ASM:

Bug 11707302 - Corruption from ASM crash during rebalance diskgroup. Misplaced Blocks (Doc ID 11707302.8)

All Known Oracle Defects:

OERR: ORA-1578 "ORACLE data block corrupted (file # %s, block # %s)" Master Note (Doc ID 1578.1)