IT06843: A SECOND START H1H2H3 WILL TERMINATE THE METRO MIRROR TARGET, TO RECOVER FROM A FAILURE TO TRANSITION FROMGM TO MGM.

Refresh Pack 5.2.6 (June 2015) for Tivoli Storage Productivity Center
Refresh Pack 5.2.7 (August 2015) for Tivoli Storage Productivity Center
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)
Fix Pack 5.2.7.1 (February 2016) for Tivoli Storage Productivity Center

APAR status

• Closed as program error.

Error description

• Certain error conditions on the hardware can cause the
  transitioning states of an MGM session to fail at the
  incremental resynch process during transition of an MGM session
  from Global Mirror mode (2 site, H1->H3 or H2->H3 ) to Metro
  Global Mirror mode (3 site, H1->H2->H3 or H2->H1->H3).
  During the processing, TPC-R needs to terminate the MM pair to
  allow resynch of the GM pairs. If there is a hardware error that
  prevents this processing from continuing, the session will get
  stuck in a Preparing / Severe state.
  Errors will be marked on the pairs that have a failure or sense
  data from the hardware, and the session will allow a Restart
  option (Start H1-> H2 ->H3, Start H2->H1 ->H3).
  If the user chooses to issue the restart, TPC-R will re-issue
  the terminate to the MetroMirror pair at the target. This has
  the unintended consequences of removing the relationships and
  bitmaps at the "middle" site, and will cause the session to
  become stuck in a Preparing / Severe state, with no options
  except for Terminate and Refresh states. At this point all
  relationships are lost at H2 and therefore manual
  re-establishment via dscli will be necessary.
  RECREATE STEPS:
  Issue a second "Start H1H2H3" command against a session which
  failed while transitioning from GM to MGM mode.  observe that
  the MetroMirror target terminates.
  ________________________________________________________________
  DB2 Version used for Server:    N/A
  The defect is against component:   5608TPC00
  Server/Manager build/release (TPC):   5.2.0
  
  ________________________________________________________________
  Problem as described by customer:   production replaction
  suspended
  Initial customer impact (low/med/high): high
  

Local fix

• If an error occurs during the transition of GM to MGM mode
  occurs:
  Do NOT attempt to reissue the H1->H2->H3 or H2->H1->H3
  commands.
  Instead, immediately take statesaves and TPC-R log package and
  contact support to determine the cause of the error and the
  state of the pairs.
  To continue TPC-R transition into the 3 site mode, determine the
  pairs that are marked with a condition or sense data code and
  either correct this condition or export all copy sets to a .csv
  file, and then remove the error copysets from the session (with
  the option to remove the relationship from the hardware).
  Doing this will allow the session to Transition into 3-site mode
  and go into a prepared state. Correct the problem on the error
  pairs and then add them back into the TPC-R MGM configuration.
  This may require IBM support or CE intervention.
  After the error pairs have been recovered ,TPC-R should be able
  now to assimilate the base  Metro Mirror and Flash Copy
  relationships (but not GM lsssession, so ensure that the pairs
  are not members of a GM session prior to adding).
  

Problem summary

• | 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.
  
  The problem occurs with MGM sessions that are transferred back
  into an H1-H2-H3 config from  GC mode (H1-H3) OR into
  H2-H1-H3 config from GC mode H2-H3. As part of the processing
  for recovery a terminate is issued to the secondaries. This is
  required to establish the new relationship for the transitional
  post processing. IFF an error occurs during the processing,
  TPC-R allows the command to be re-issued. Once the command is
  reissued a second terminate command is issued to the secondary
  which destroys the bitmap and causes the secondary to become
  simplex and has no knowledge of the relationship. This requires
  the relationship to now be re-established and a full copy is
  needed
  

Problem conclusion

• A second restart will no longer issue a second terminate as long
  as the first terminate has completed successfully.
  

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

• R525 PSN

     UP