PH70427: ABEND 0C4-00000038 IN DSNB1REL+01894

APAR status

• Closed as program error.

Error description

• Abend and hang may occur if a storage allocation request for
  storage needed for a buffer manager PMB control structure
  returns previously used dirty storage,  then this abend may
  occur.   This is considered to be rare.   If the storage had
  been previously freed by an IARV64 with REQUEST(DETACH) which is
  the norm,  then the storage will be clean.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Db2 13 for z/OS users.                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: ABEND 0C4-00000038 DSNB1REL             *
  ****************************************************************
  * RECOMMENDATION: Apply corrective PTF when available          *
  ****************************************************************
  When allocating virtual storage for buffer pools with
  PGSTEAL(LRU) or PGSTEAL(FIFO), Db2 uses the macro in z/OS that
  provides virtual storage services. However, in rare cases the
  storage returned for the control blocks related to the
  buffer pool may not be initialized. Db2 code was assuming the
  acquired storage for the buffer pool control blocks is always
  initialized. Thus it can result in
  ABEND 0C4-00000038 at location DSNIDM DSNB1REL OFFSET01894 or
  ABEND 0C4-00000038 at location DSNIDM DSNB1REL OFFSET0190E.
  

Problem conclusion

• Db2 code has been modified to initialize the control blocks
  after buffer pool storage allocation for a PGSTEAL(LRU) or
  PGSTEAL(FIFO) buffer pool.
  

Temporary fix

Comments

APAR Information

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

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

  UO07398

Modules/Macros

• DSNB1ABS
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels