Zeroed ASM blocks (Doc ID 1997517.1)

Last updated on MAY 06, 2015

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.2 to 12.1.0.2 [Release 11.2 to 12.1]
Information in this document applies to any platform.

Symptoms

1. ASM reports one or several corrupted blocks in the alert log file, laong with the error ORA-15196:

WARNING: cache read  a corrupt block: group=1(<DISKGROUP>) dsk=0 blk=1 disk=0 (<DISK>) incarn=3916383599 au=0 blk=1 count=1
Errors in file <trace file>

ORA-15196: invalid ASM block header [kfc.c:26076] [endian_kfbh] [2147483648] [1] [0 != 1]
NOTE: a corrupted block from group CRSDG was dumped to <trace file>

2. AMDU reports metadata corrupted blocks in the file report.txt:

------------------------ SUMMARY FOR DISKGROUP <DISKGROUP>------------------------
          Allocated AU's: 253711
               Free AU's: 145649
      AU's read for dump: 15
      Block images saved: 1273
       Map lines written: 15
         Heartbeats seen: 0
 Corrupt metadata blocks: 768  ------>  HERE
       Corrupt AT blocks: 2        ------>  HERE

 

3. kfed reveals the blocks, several of them are zeroes:


$kfed read <disk1> aunum=0 blknum=1

kfbh.endian:                          0 ; 0x000: 0x00
kfbh.hard:                            0 ; 0x001: 0x00
kfbh.type:                            0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt:                          0 ; 0x003: 0x00
kfbh.block.blk:                       0 ; 0x004: blk=0
kfbh.block.obj:                       0 ; 0x008: file=0
kfbh.check:                           0 ; 0x00c: 0x00000000
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
2B98D2EFF400 00000000 00000000 00000000 00000000  [................]
  Repeat 255 times


$kfed read <disk2> aunum=0 blknum=2

kfbh.endian:                          0 ; 0x000: 0x00
kfbh.hard:                            0 ; 0x001: 0x00
kfbh.type:                            0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt:                          0 ; 0x003: 0x00
kfbh.block.blk:                       0 ; 0x004: blk=0
kfbh.block.obj:                       0 ; 0x008: file=0
kfbh.check:                           0 ; 0x00c: 0x00000000
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
2B2D30FBB400 00000000 00000000 00000000 00000000  [................]
  Repeat 255 times


$kfed read <disk3> aunum=0 blknum=3

kfbh.endian:                          0 ; 0x000: 0x00
kfbh.hard:                            0 ; 0x001: 0x00
kfbh.type:                            0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt:                          0 ; 0x003: 0x00
kfbh.block.blk:                       0 ; 0x004: blk=0
kfbh.block.obj:                       0 ; 0x008: file=0
kfbh.check:                           0 ; 0x00c: 0x00000000
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
2B9D91687400 00000000 00000000 00000000 00000000  [................]
  Repeat 255 times

 

The output shown above was collected from different disks, which belong to different diskgroups.  Development found blocks 1,2,3 and 4 were all zeroes.

Cause

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