PM08098: DB2 CRASHES AFTER RC00E20029 DSNB1CPP DSNSVBK. SMCOVERLAY DB2OVRLAY/K

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After ABEND04E RC00E20029 from DSNB1CPP DSNSVBK DB2
  terminates abnormally.
  PBL indicates one more partition than actually allocated.
  Additional Symptoms:
  ABEND04E RC00E50005 in DSNSVBK
  ABEND0C4 in DSNB1CPS
  ABEND04E RC00C200C9 in DSNB1CHK
  ABEND04E RC00C202AA in DSNB1PER ( data sharing only )
  ABEND04E RC00C20300 in DSNICMT2
  ABEND0C4 PIC38 in DSNILCLO, the list of PB0s from the
  PB shows it was built for and incorrect number of partitions.
  
  Other symptoms may result from possible storage overlays.
  In a non Data Sharing environment only, data loss may occur.
  INCORROUT
  DB2STGLK/K
  DB2INCORR/K
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: DB2 users.                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: Storage overlays involving various      *
  *                      pageset control blocks, after an ALTER  *
  *                      TABLE ADD PART has been done for a      *
  *                      partitioned tablespace.  SMCOVERLAY.    *
  *                                                              *
  *                      Symptoms of storage overlays include:   *
  *                       - ABEND04E RC00E20029 in DSNSVBK       *
  *                       - ABEND04E RC00E50005 in DSNSVBK       *
  *                       - ABEND0C4 in DSNB1CPS                 *
  *                       - ABEND04E RC00C200C9 in DSNB1CHK      *
  *                       - ABEND04E RC00C202AA in DSNB1PER      *
  *                         (data sharing only)                  *
  *                                                              *
  *                      In a non-data-sharing system, broken    *
  *                      data may result from having two         *
  *                      instances of a pageset open at the      *
  *                      same time.  Symptoms include:           *
  *                       - Incorrect output, INCORROUT.         *
  *                       - ABEND04E RC00C90101, RC00C90102,     *
  *                         RC00C90105, or RC00C902xx in         *
  *                         various CSECTS.                      *
  *                       - Data/index inconsistencies reported  *
  *                         by the CHECK INDEX utility.          *
  *                       - Page regression reported by the      *
  *                         DSN1LOGP utility.                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  It is possible for an ALTER TABLE ADD PART to be issued while
  some other agent has a PSCB block allocated for the table space
  or one of its indexes.  If that agent continues to use this PSCB
  after the ALTER completes, and requests physical opens, claims
  or drains, storage overlays may occur due to using new part
  number(s) with blocks which were only allocated large enough
  for the original number of parts.  These storage overlays can
  cause various abends, and may result in DB2 crashing.
  
  In a non-data-sharing system, it is possible that a down-level
  control block can result in physically opening the same page
  set twice, under two sets of control blocks.  If updates are
  done to both instances, some of these updates will be lost,
  resulting in broken data.
  

Problem conclusion

• The page set open logic has been modified to ensure that a
  global page set control block (PB) will not continue to be used
  if the number of partitions or logical partitions has been
  changed.  Additionally, any claim or drain request for a part
  number which is beyond the scope of the PSCB will now result in
  an immediate abend, rather than allowing the PSCB storage to be
  overlaid.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UK56285 UK56286

Modules/Macros

• DSNB1CLM DSNB1DRA DSNB1LCM DSNB1LDN DSNB1OPS
  DSNIPSI
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R810 PSY UK56285

     UP10/05/06 P F005

• R910 PSY UK56286

     UP10/05/06 P F005

Fix is available

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