IT07853: MGM WITH HYPERSWAP WILL UNFENCE THE PRIMARY VOLUME AFTER A HYPERSWAP

IBM Spectrum Control V5.2.8 (December 2015)
IBM Spectrum Control V5.2.9 (February 2016)
IBM Spectrum Control V5.2.10 (May 2016)
IBM Spectrum Control V5.2.10.1 (July 2016)
IBM Spectrum Control V5.2.11 (August 2016)
IBM Spectrum Control V5.2.12 (November 2016)
IBM Spectrum Control V5.2.13 (March 2017)
IBM Spectrum Control V5.2.14 (May 2017)
IBM Spectrum Control V5.2.15 (August 2017)
IBM Spectrum Control V5.2.15.2 (November 2017)
IBM Spectrum Control V5.2.16 (March 2018)
IBM Spectrum Control V5.2.17 (May 2018)
Refresh Pack 5.2.6 (June 2015) for Tivoli Storage Productivity Center
Refresh Pack 5.2.7 (August 2015) for Tivoli Storage Productivity Center
Fix Pack 5.2.7.1 (February 2016) for Tivoli Storage Productivity Center

APAR status

• Closed as program error.

Error description

• After a hyperswap is performed on a MGM session it is necessary
  to terminate the MM portion of the relationship at the
  secondary in order to set up for transition to allow Start
  H1->H2->H3 or Start H2->H1->H3. If the relationship is not
  terminated processing will be unable to continue and the session
   will be in a partially failed over state. Sessions all use
  common code that sets up when to remove soft fence. This common
  code was put in place to avoid hitting an error F79, which if
  hit would leave the relationship stuck until the soft fence is
  removed by the user. While some newer hardware supports commands
   through a soft fence, older hardware is susceptible to hitting
  the error and will not allow the terminate leaving the source
  volumes as primary simplex and only the secondaries know that
  they are in a relationship. This apar will change to not ever do
   a soft fence (which may leave some customers vulnerable to a
  partial terminate and MGM processing cannot continue until the
  soft fence is removed). It is suggested that PRIOR to re-issuing
   the Start H1->H2->H3 or Start H2->H1->H3 the soft fence should
  be removed from the primaries
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Customers running Metro Global Mirror with Hyperswap who     *
  * encounter a hyperswap by event                               *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * | fix pack | 5.2.6-TIV-TPC-FP0000 - target 2Q 2015 |         *
  *                                                              *
  *                                                              *
  * http://www-01.ibm.com/support/docview.wss?&uid=swg21320822   *
  *                                                              *
  * The target dates for future fix packs do not represent a     *
  * formal                                                       *
  * commitment by IBM. The dates are subject to change without   *
  * notice.                                                      *
  *                                                              *
  * After encountering a hyperswap  by event TPC-R will unfence  *
  * the primary in order to continue processing to set up for    *
  * the next available command state. With the release of "Soft  *
  * fence" support on the DS8000 and zOS release, this is no     *
  * longer necessary. Therefore TPC-R should not unfence the     *
  * primaries.                                                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * none                                                         *
  ****************************************************************
  

Problem conclusion

• A check was added for MGM sessions that are hyperswap enabled to
  not remove the soft fence during the terminate sub action
  

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:

Fix information

• Fixed component name

  TPC

• Fixed component ID

  5608TPC00

Applicable component levels

• R520 PSY

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