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IC78236: DB MARKED BAD IF BACKUP ENCOUNTERS BAD LOB ALLOCATION PAGE ON SMS TABLESPACE

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • When DB2 hits a bad LOB allocation page on a SMS tablespace
    during backup, the current action is to mark the database bad.
    This APAR improves resiliency such that DB2 will no longer mark
    the database bad, but instead abort the backup and return a
    SQL1656C error. Other, non-backup accesses to this bad LOB
    object will still likely mark the database bad. As a result,
    repairing the bad LOB allocation data should still be a
    priority.
    
    When a bad LOB allocation page on an SMS tablespace is hit, the
    db2diag.log shows the error below from function
    sqldxDirectReadAllocMap. If the APPHDL of the error message
    matches that of a backup message (an example of which is also
    given below), the bad LOB allocation page was hit by backup.
    
    
    
    2011-07-24-10.25.49.338904-300 E980332A458        LEVEL: Info
    PID     : 836098               TID  : 21626       PROC : db2sysc
    136
    INSTANCE: db2sampl             NODE : 136         DB   :
    CRD_PROD
    APPHDL  : 136-31580            APPID:
    *N136.db2sampl.110724205334
    AUTHID  : DB2SAMPL
    EDUID   : 21626                EDUNAME: db2agent (CRD_PROD) 136
    FUNCTION: DB2 UDB, database utilities, sqlubSetupJobControl,
    probe:1601
    MESSAGE : Starting an online db backup.
    
    
    2011-07-24-10.51.36.308283-300 I998432A1392       LEVEL: Severe
    (Origin)
    PID     : 836098               TID  : 19205       PROC : db2sysc
    136
    INSTANCE: db2sampl             NODE : 136         DB   :
    CRD_PROD
    APPHDL  : 136-31580            APPID:
    *N136.db2sampl.110724205334
    AUTHID  : DB2SAMPL
    EDUID   : 19205                EDUNAME: db2bm.21626.0 (CRD_PROD)
    136
    FUNCTION: DB2 UDB, lob manager, sqldxDirectReadAllocMap,
    probe:889
    DATA #1 : Buddy Segment Address, PD_TYPE_BSEG_ADDR, 4 bytes
    0
    DATA #2 : Hex integer, 1 bytes
    0x00
    CALLSTCK:
      [0] 0x090000000780FEA4 pdLog + 0xD0
      [1] 0x0900000005CEFBE0
    sqldx_dumpBadPage__FP9SQLDX_LWAP17SQLDX_CACHE_ENTRYUiiT4CUle +
    0xA90
      [2] 0x0900000005CEF074
    sqldx_dumpBadPage__FP9SQLDX_LWAP17SQLDX_CACHE_ENTRYUiiT4CUle@glu
    e14B8
    + 0xE0
      [3] 0x09000000032EC740
    sqldxDirectReadAllocMap__FP9SQLDX_LWAP17SQLDX_CACHE_ENTRYUiT3PiP
    Us
    + 0xEC
      [4] 0x09000000078F9ED4
    sqldxReadAllocMap__FP9SQLDX_LWAP17SQLDX_CACHE_ENTRYUiT3PiPUs +
    0x64
      [5] 0x090000000442F624
    sqldxLobScan__FP9SQLDX_LWAP14SQLDX_LBA_INFOP17SQLDX_CACHE_ENTRYT
    3UsUlP9SQLP_LSN8bPlPUi
    + 0x488
      [6] 0x0900000004487318
    sqldxReadLobFileForBackup__FP8sqeAgentP8SQLD_TCBlPUiPlP9SQLP_LSN
    8Ul
    + 0x4F0
      [7] 0x0900000004485060
    sqlubReadLOB__FP14SQLU_BUFMAN_CBP8SQLD_TCB + 0x158
      [8] 0x09000000044823E8 sqlubReadSMS__FP14SQLU_BUFMAN_CB +
    0x26C
      [9] 0x09000000044802D0 sqlubBMCont__FP14SQLU_BUFMAN_CB + 0xB30
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * DB2 would mark database bad when backing up bad LOB          *
    * allocation data on a SMS tablespace. This APAR will make DB2 *
    * return a SQL1656C instead.                                   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 V9.7 Fix Pack 6.                              *
    ****************************************************************
    

Problem conclusion

  • This problem was first fixed in DB2 V9.7 Fix Pack 6.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC78236

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    970

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-08-19

  • Closed date

    2012-06-12

  • Last modified date

    2012-06-12

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IC78236

Modified date: 12 June 2012