IJ40947: FINE GRAIN WRITE SHARING HINT MAY CAUSE FILE CONTENT IN SNAPSHOT TO BE CHANGED

APAR status

• Closed as program error.

Error description

• When an user application uses the Fine Grain Write
  Sharing hint,  GPFS_FINE_GRAIN_WRITE_SHARING, to overwrite
  an existing file which is also in a snapshot, there is a
  possibility that the file content in the
  snapshot won't be preserved but
  will be changed to be the same as the
  file content in the active file system.
  

Local fix

Problem summary

• When an user application uses the Fine Grain Write
  Sharing hint,  GPFS_FINE_GRAIN_WRITE_SHARING, to overwrite
  an existing file which is also in a snapshot, there is a
  possibility that the file content in the
  snapshot won't be preserved but
  will be changed to be the same as the
  file content in the active file system.
  

Problem conclusion

• This problem is fixed in 5.1.4 PTF 1
  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:
  
  The file content in a snapshot will be preserved,
  as expected, even if the file in the
  active file system is overwritten
  via the GPFS_FINE_GRAIN_WRITE_SHARING hint.
  
  Work around:
  None
  Problem trigger:
  Use the GPFS_FINE_GRAIN_WRITE_SHARING hint to
  overwrite an existing file which is also in a snapshot
  Symptom:
  Data loss in the snapshot file when the
  GPFS_FINE_GRAIN_WRITE_SHARING hint to used to
  overwrite the file in the active file system.
  Platforms affected:
  Linux
  Functional Area affected:
  All Scale Users using the GPFS_FINE_GRAIN_WRITE_SHARING
  hint and snapshots at the same time.
  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