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IT20923: EXTENT MOVEMENT WITH NATIVE ENCRYPTION COULD LEAD TO CORRUPTED PAGE ONLY IN-MEMORY

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APAR status

  • Closed as program error.

Error description

  • With native encryption enabled and extent movement running
    (ALTER TABLESPACE [REDUCE MAX|LOWER HIGH WATER MARK]) it is
    possible to have part of a page corrupted in-memory only. The
    permanent on-disk data remains consistent.
    
    If this issue is hit, there are two type of message which may be
    found in db2diag.log:
    
    2017-06-06-08.56.29.647685+000 I553658936E503        LEVEL:
    Severe
    PID     : 39893                TID : 46913034381056  PROC :
    db2sysc 18
    INSTANCE: db2inst1             NODE : 018            DB   :
    BLUDB
    HOSTNAME:
    EDUID   : 275                  EDUNAME: db2pclnr (BLUDB) 18
    FUNCTION: DB2 UDB, buffer pool services,
    sqlbCommonWriteCompletion, probe:3541
    DATA #1 : String, 65 bytes
    Error detected in page decryption after successful write to
    disk.
    
    2017-06-06-08.56.29.649731+000 I553659440E187     LEVEL: Severe
    PID:39893 TID:46913034381056 NODE:018 Title: SQLB_PAGE
    Dump
    File:/head/home/db2inst1/sqllib/db2dump/39893.275.018.dump.bin
    
    2017-06-06-08.56.29.656855+000 I553659628E3516       LEVEL:
    Severe
    PID     : 39893                TID : 46913034381056  PROC :
    db2sysc 18
    INSTANCE: db2inst1             NODE : 018            DB   :
    BLUDB
    HOSTNAME:
    EDUID   : 275                  EDUNAME: db2pclnr (BLUDB) 18
    FUNCTION: DB2 UDB, buffer pool services,
    sqlbCommonWriteCompletion, probe:3560
    
    OR the more common message:
    
    2016-11-23-05.32.32.445845+000 I1626993E4191         LEVEL:
    Severe
    PID     : 46763                TID : 139562965788416 PROC :
    db2sysc 71
    INSTANCE:             NODE : 071            DB   :
    APPHDL  : 71-2440              APPID:
    AUTHID  :             HOSTNAME:
    EDUID   : 5155                 EDUNAME: db2agent (DBEDWP1) 71
    FUNCTION: DB2 UDB, Common Trace API, sqlbfix, probe:648
    DATA #1 : String, 1046 bytes
    ASSERTION FAILED!!!
    ASSERTION EXPRESSION: (( (
    (((((curPage))->pagehead.revnum)&0x0F00) == (0x0500 & 0x0F00))
    && ( (( ((sqlbGetBeginDataOffset(((curPage)))) ==
    sizeof(SQLB_PAGE_HEAD)) &&
    (((sqlbGetBeginDataOffset(((curPage)))) +
    sqlbGetDataLen(((curPage)))) == (U32BIT)((pageSize))) )) || ((
    ((sqlbGetBeginDataOffset(((curPage)))) == 0x0032) &&
    (((sqlbGetBeginDataOffset(((curPage)))) +
    sqlbGetDataLen(((curPage))) + sizeof(SQLP_LSN6)) ==
    ((size_t)4096) ) )) ) ) || ( (
    (((((curPage))->pagehead.revnum)&0x0F00) == 0x0400) ||
    (((((curPage))->pagehead.revnum)&0x0F00) == 0x0300) ) && ((
    ((sqlbGetBeginDataOffset(((curPage)))) ==
    sizeof(SQLB_PAGE_HEAD)) &&
    (((sqlbGetBeginDataOffset(((curPage)))) +
    sqlbGetDataLen(((curPage)))) == (U32BIT)((pageSize))) )) ) || (
    (((((curPage))->pagehead.revnum)&0x0F00) == 0x0200) && ((
    ((sqlbGetBeginDataOffset(((curPage)))) == 0x0032) &&
    (((sqlbGetBeginDataOffset(((curPage)))) +
    sqlbGetDataLen(((curPage))) + sizeof(SQLP_LSN6)) ==
    ((size_t)4096) ) )) ) ))
    

Local fix

  • Either:
    1) Turn off native encryption
    2) Do not run extent movement
    3) Get the code fix
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Users who use native encryption with extent movement         *
    * operations.                                                  *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Install latest fix pack.                                     *
    ****************************************************************
    

Problem conclusion

  • Install latest fix pack.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT20923

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-06-07

  • Closed date

    2017-06-26

  • Last modified date

    2017-06-26

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

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

    IT20925

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
29 June 2020