This problem exists on the Linux platform only.
Conditions through which the Bad Page Header is encountered:
1) Linux operating system
2) DB2 V9.8
3) Tablespaces with multiple containers
4) Online backup
5) Significant user activity which drives prefetching during
online backup
There are 2 possible consequences:
1) Incorrect pages are silently written to the online backup.
Any restore from this backup image will result in data
corruption.
2) Bad Page Header messages encountered by prefetchers during
the online backup.
2011-06-01-21.04.29.871752-240 I495774E3614 LEVEL: Severe
PID : 11263 TID : 47129540159808PROC :
db2sysc
INSTANCE: db2inst1 NODE : 000
EDUID : 134 EDUNAME: db2pfchr (SAMPLE)
FUNCTION: DB2 UDB, buffer pool services, sqlb_verify_page,
probe:13
MESSAGE : ZRC=0x87020036=-2029912010=SQLB_BADHDR "Bad Page
Header"
DIA8547C An error occurred in a database page header.
DATA #1 : String, 64 bytes
Error encountered trying to read a page - information follows :
DATA #2 : String, 23 bytes
Page verification error
DATA #3 : Page ID, PD_TYPE_SQLB_PAGE_ID, 4 bytes
9678
DATA #4 : Object descriptor, PD_TYPE_SQLB_OBJECT_DESC, 88 bytes
Obj: {pool:4;obj:4;type:1} Parent={4;4}
lifeLSN: 0000000010F75884
tid: 0 0 0
extentAnchor: 8490
initEmpPages: 0
poolPage0: 0
poolflags: 3122
objectState: 27
lastSMP: 0
pageSize: 16384
extentSize: 2
bufferPoolID: 2
partialHash: 17039364
bufferPool: 0x00002adc27f347c0
pdef: 0x00002adc2de8aec0
DATA #5 : Bitmask, 4 bytes
0x00000002
DATA #6 : Page header, PD_TYPE_SQLB_PAGE_HEAD, 48 bytes
pageHead: {tbspSeed:4;obj:4;type:0} PPNum:2770 OPNum:2762
begoff: 48
datlen: 16336
pagebinx: 0
revnum: 1280
pagelsn: 000000000238ED4C flag: 2
future32: 0
cbits1to31: 1c02807
cbits32to63: 0
CALLSTCK:
[0] 0x00002ADBBF2955A2 pdLog + 0x398
[1] 0x00002ADBBFF73186
_Z25sqlbLogReadAttemptFailurejP16SQLB_OBJECT_DESCjP9SQLB_PAGEibm
jPcP12SQLB_GLOBALS
+ 0x1BE
[2] 0x00002ADBC1A59352
_Z16sqlb_verify_pageP9SQLB_PAGEP16SQLB_OBJECT_DESCjjP12SQLB_GLOB
ALSPm
+ 0x376
[3] 0x00002ADBBF2CDFF8
_Z25sqlbReadAndReleaseBuffersP16SQLB_OBJECT_DESCjmmmP11SQLB_pfMi
sc
+ 0x984
[4] 0x00002ADBBF2CC538
_Z16sqlbProcessRangeP16SQLB_OBJECT_DESCjjP11SQLB_pfMisc + 0x140
[5] 0x00002ADBBF2CB7B7
_Z26sqlbPFPrefetcherEntryPointP16sqbPrefetcherEdu + 0x3C9
[6] 0x00002ADBBF2CB3AD _ZN16sqbPrefetcherEdu6RunEDUEv + 0x2F
[7] 0x00002ADBBFA9732C _ZN9sqzEDUObj9EDUDriverEv + 0xA6
[8] 0x00002ADBBFA97283 _Z10sqlzRunEDUPcj + 0x9
[9] 0x00002ADBBF80B3D2 sqloEDUEntry + 0x2F4
The db2diag.log entries in the above example show that DB2
requested page 9678 from tablespace 4, but received page 2770
from tablespace 4. In order to verify the occurrence of the bad
page header issue, the received page must be in the same
tablespace as the requested page. |
