VMAX3: SRDF/A falling behind and unable to keep up with Minimum Cycle Switch Time

Summary: VMAX3: SRDF/A falling behind and unable to keep up with Minimum Cycle Switch Time.

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Symptoms

  • SRDF Move pair
  • SRDF Sync of invalid tracks
 
  • SRDF/A Spillover spilling tracks
  • SRDF/A device pair stuck sync in progress while there is Spilled tracks (optional)
  • SRDF ports are not busy, but we are waiting for tracks to be spilled back before being able to transmit them to the R2

Cause

This is a HYPERMAX OS issue. Once the SRDF/A group starts to spillover, it is never able to catch up again. This is much more likely to occur with large cycles. By default, the code allows to request spill back of cycles up to 30 seconds in age. With the default 15 second cycle switch time this means that we consider the Transmit, Transmit+1, and Transmit+2 cycles. With each cycle we limit ourselves to 30 superslices (42 tracks each) which are actively allowed to be in progress of spilling back.
If detecting that there is already this many in progress then no further requests are made for that specific cycle.

Resolution

  • If you believe, you have encountered this issue please contact the Support Center for assistance and quote this article ID.
  • Engineering can be engaged to apply a temporary change in the code to allow the cycles to catch up. 
  • Fix 96451 is available by Reactive Epack request to resolve this problem.

Affected Products

SRDF/Asynchronous, VMAX3 Series
Article Properties
Article Number: 000064045
Article Type: Solution
Last Modified: 13 Aug 2025
Version:  5
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