OA47007: XRC RC901 OR DYNAMIC VOLUME COMPARE MISMATCH FOLLOWING MZGM RESYNCHRONIZATION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• In an MzGM IR environment, suspending or canceling XRC while a
  volume is both resynchronizing and being updated may result in
  data not being copied to the secondary on subsequent
  resynchronization. Problem is most likely to occur if mirroring
  is interrupted during a period of high session delay shortly
  after a large number of volumes have reached duplex.
  
  Additional keywords:
  RC=0901, ABEND9C4-10, ABEND9C4-2C, Dynamic Volume Compare
  (ANTUXDVC) mismatch
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of MzGM IR.                            *
  ****************************************************************
  * PROBLEM DESCRIPTION: In an MzGM environment, suspending or   *
  *                      canceling XRC while a volume is both    *
  *                      synchronizing or re-synchronizing and   *
  *                      being updated may result in data not    *
  *                      being copied to the secondary on        *
  *                      subsequent resynchronization.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  

Problem conclusion

• Problem has been fixed.
  
  Here is the action hold that is included in the PTFs:
  
  Users of MzGM IR, whose sessions have been exposed to the
  failure scenario described below, should take action to ensure
  the integrity of data on their secondary volumes.
  
  The scenario involves an XRC primary volume that is being
  written to while that volume is being synchronized or
  re-synchronized in an MzGM IR session. If, during the
  synchronization, the volume gets suspended for any reason
  before duplex or shortly after duplex, it is possible that
  subsequent re-synchronization will result in data not being
  copied correctly to the secondary. It is also possible that a
  901 RC, 9C4-10, or 9C4-2C may be seen as a result of this bug.
  Note that this is only for an MzGM IR session. Non-IR XRC
  sessions are unaffected by this bug.
  
  Not every instance of this scenario will cause incorrect data
  to be written, but only a volume compare between primary and
  secondary can tell for certain.
  
  If volumes have undergone a full copy (XEND or XDELPAIR and
  re-add) since being exposed to the failure scenario, then the
  problem has been corrected and no further action is needed.
  
  If volumes have not undergone a full copy since being exposed
  to the failure scenario, or if you are not sure whether or not
  exposure occurred, then the following action should be taken:
  
  - XSUSPEND TIMEOUT or XEND all MzGM IR sessions.
  - Install this PTF according to HOLD(RESTART) instructions.
  - If XENDed:
    - Start MzGM IR sessions and perform full copy on all
      XRC volumes
  - If XSUSPEND TIMEOUT:
    - Restart MzGM IR sessions
    - XDELPAIR suspected volumes
    - XADDPAIR all volumes with the XDELPAIRed volumes
      performing a full copy.
  
  As an alternative, contact IBM for instructions on using a
  dynamic volume compare program to identify volumes that have
  discrepancies, so that they can be individually recopied.
  KEYWORDS: D/T2105 D/T2107 XRC/K
  

Temporary fix

• *********
  * HIPER *
  *********
  INSTALL ++APAR.
  

Comments

APAR Information

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

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

  UA81468 UA81469 UA81470

Modules/Macros

• ANTS4022
  

Fix information

• Fixed component name

  SYSTEM DATA MOV

• Fixed component ID

  5695DF117

Applicable component levels

• RD10 PSY UA81468

     UP16/04/29 P F604 Ž

• R210 PSY UA81469

     UP16/04/29 P F604 Ž

• R220 PSY UA81470

     UP16/04/29 P F604 Ž

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.