IJ49086: SLOW FILE CREATE PERFORMANCE WHEN CONCURRENTLY CREATE MANY SMALLFILES.

APAR status

• Closed as program error.

Error description

• File create performance could degrade when concurrently create
  many small files in many directories due to mutex contention.   
  This would also lead to higher CPU usage by GPFS daemon.
  

Local fix

• Set maxInodeDeallocHistory configuration variable to 0
  

Problem summary

• File create performance could degrade when concurrently create
  many small files in many directories due to mutex contention.   
  This would also lead to higher CPU usage by GPFS daemon.
  

Problem conclusion

• This problem is fixed in 5.1.2.14
  To see all Spectrum Scale APARs and their respective
  Fix solutions refer to page:
  https://public.dhe.ibm.com/storage/spectrumscale/spectrum_scale_
  apars.html
  
  Benefits of the solution:
  Reduce chance of mutex contention when there are heavy
  concurrent create of small files.
  
  Work Around:
  Set maxInodeDeallocHistory configuration variable to 0
  
  Problem trigger:
  Concurrent create of many small files in many directories
  
  Symptom:
  Performance Impact/Degradation
  
  Platforms affected:
  ALL Operating System environments
  
  Functional Area affected:
  All Scale Users
  
  Customer Impact:
  High Importance
  

Temporary fix

Comments

APAR Information

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

• 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