IJ51248: DISK OPERATION ERROR; PATH HAS FAILED

APAR status

• Closed as program error.

Error description

• After migrating from non-multi-queue to multi-queue
  on AIX, customer might experience higher latency for
  IO, when all channels are loaded evenly.
  

Local fix

• Realloc buffers when there is change from
  non-multi-channel to
  multi-channel client. This reduces the risk of getting
  into the
  starvation issue. The logic accounts for enough local
  bufs per
  channel.
  

Problem summary

• After migrating from non-multi-queue to multi-queue on AIX,
  which is moving from something lower to Version 7.2 Technology
  Level 05, or later,  AIX lpar virtual adapters experience
  higher latency for IO and disk operation errors due to command
  timeout.
  

Problem conclusion

• Realloc buffers on VIOS vfc host when there is change from
  non-multi-channel to multi-channel client. This reduces the
  risk of getting into the starvation issue. The logic accounts
  for enough local bufs per channel.
  

Temporary fix

Comments

APAR Information

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

  IJ48765

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

Fix information

• Fixed component name

  AIX V7.3

• Fixed component ID

  5765CD300

Applicable component levels