IJ32361: POOR WRITE PERFORMANCE OBSERVED FROM AN APPLICATION

APAR status

• Closed as program error.

Error description

• After convert legacy recovery group to
  mmvdisk managed recovery group,
  poor write performance observed from an application
  and the gpfs daemon did not come up because
  of OOM issue on the some nodes.
  

Local fix

• Using the following command to reset the pagepool to 60%:
  mmvdisk server change --node-class NcName
  --pagepool 60% --recycle one
  

Problem summary

• After convert legacy recovery group to
  mmvdisk managed recovery group,
  poor write performance observed from an application
  and the gpfs daemon did not come up because
  of OOM issue on the some nodes.
  

Problem conclusion

• Benefits of the solution:
  Write performance is improved for customer application
  
  Work Around:
  Using the following command to reset the pagepool to 60%:
  mmvdisk server change --node-class NcName
  --pagepool 60% --recycle one
  
  
  Problem trigger:
  When convert legacy recovery group to mmvdisk
  managed recovery group by following command:
  mmvdisk recoverygroup convert --recovery-group
  RgName[,RgName] --node-class NcName
  
  Symptom:
  Abend/Crash
  Performance Impact/Degradation
  
  Platforms affected:
      ALL Linux OS environments
  
  Functional Area affected:
      ESS/GNR
  
  Customer Impact:
      Suggested
  

Temporary fix

Comments

APAR Information

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

  IJ32223

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

Fix information

• Fixed component name

  SPEC SCALE STD

• Fixed component ID

  5737F33AP

Applicable component levels