IT03277: GM FLASH CMD USING PAUSE WITH CONSISTENCY TOOK LONGER THAN EXPECTED

Tivoli Storage Productivity Center Refresh Pack 4
Fix Pack 5.2.4 (November 2014) for Tivoli Storage Productivity Center
Fix Pack 5.2.4.1 (December 2014) for Tivoli Storage Productivity Center
Refresh Pack 5.2.5 (March 2015) for Tivoli Storage Productivity Center (withdrawn)
Fix Pack 5.2.5.1 (April 2015) for Tivoli Storage Productivity Center (withdrawn)
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 fixed if next.

Error description

• Running Flash cmd for a GM/Practice volume session took longer
  time than expected. There are 2 potential fixes to decrease the
  time:
  1. Remove the step to reflash I2 to J2
  2. In the ESSGMDriver start method to setup flashes for I2J2,
  spinning off threads to do some of the flashes in parallel.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users that issue a flash command to a Global Mirror with     *
  * practice session and have large amounts of copysets.         *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * | fix pack | 5.2.4-TIV-TPC-FP0000 - target 1Q 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.                                                      *
  *                                                              *
  * There are two main issues with the current function that is  *
  * leading to a long Flash time.                                *
  * 1) Re-Flash I2 to J2 doesn't need to be done.  After it has  *
  * been determined that the FRR is not needed, the I2J2         *
  * relationship does not need to be changed because the         *
  * relationship is still on the hardware.  This step is there   *
  * because without Pause with Consistency the flash             *
  * relationships have to be rebuilt.  So if Pause with          *
  * Consistency is enabled the incremental flash is useless here *
  * and should be skipped.                                       *
  * 2) In the Global Mirror Driver start method when the setup   *
  * flashes for I2J2, each operation is done serially.  This     *
  * should be threaded to do some of the flashes in parallel. If *
  * there are hundreds of different drivers all running serially *
  * each driver (lss-lss pairing) will add to the time it takes  *
  * to complete the flash.                                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * none                                                         *
  ****************************************************************
  

Problem conclusion

• Function will be added to detect whether Pause with consistency
  is supported on the underlying device and if it is enabled will
  skip the re flash of I2 to J2. Secondly the flashes on this pair
  will be done in parallel rather than serially.
  

Temporary fix

Comments

APAR Information

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

  PI22608

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

Fix information

Applicable component levels

• R520 PSY

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