  Volume Shadowing, Contention and MPSYNC? 
 The Question is:
 
We are having a problem with MP Sync mode being excessive (200% out of 400%)
 during shadow set copying.  Is this normal or should I look at changing some
 of the SMP parameters.
 
Thanks,
Phil
 
 
 The Answer is :
 
  The OpenVMS Wizard will assume you have the current shadowing ECO
  kit installed.  If so, please check the associated documentation
  for the available volume shadowing adjustments and mechanisms.
  If not, please install the current shadowing ECO kit.
 
  Additionally, an upgrade to a more current OpenVMS Alpha release can
  relieve a number of the potential causes of excessive multiprocessor
  synchronization (MPSYNC) waits; can help eliminate various common
  sources of contention.
 
  There are no plans to backport various of these contention-reduction
  improvements to earlier OpenVMS releases.
 
  In isolation, tracking the cause of MPSYNC requires specific details
  on the system activity during the contention; tracking requires some
  idea of the specific synchronization contention involved here.
 Answer written or last revised on  18-DEC-2002 
