IJ44887: LOGASSERTFAILED: DATABLOCKNUM != LASTDATABLOCK || !NEWDA.ISALLOC

APAR status

• Closed as program error.

Error description

• Spectrum Scale mmfsd daemon can crash with an assert like
  the one shown below. The assert is logged in the
  mmfs.log:
  
  [X] logAssertFailed: dataBlockNum != lastDataBlock ||
  !newDA.isALLOC() || newDA.getNSubblocks() ==
  inode.getLastBlockSubblocks(isWideDAFS)
  [X] return code 28, reason code 512, log record tag 256
  Assertion failed: dataBlockNum != lastDataBlock ||
  !newDA.isALLOC() || newDA.getNSubblocks() ==
  inode.getLastBlockSubblocks(isWideDAFS)
  
  
  Reported in:
  Spectrum Scale 5.1.5.1
  

Local fix

Problem summary

• mmfsd daemon assert going off:
  logAssertFailed: dataBlockNum != lastDataBlock ||
  !newDA.isALLOC() || newDA.getNSubblocks() ==
  inode.getLastBlockSubblocks(isWideDAFS),
  resulting mmfsd daemon process crash.
  

Problem conclusion

• This problem is fixed in 5.1.6.1
  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:
  Get the accurate lastBlockSubblocks, so avoid to hit this assert
  and further avoid mmfsd daemon process crash due to this issue.
  
  Work Around:
  None
  
  Problem trigger:
  Parallel writes to the same file and one write is updating to
  the last data block.
  
  Symptom:
  Abend/Crash
  
  Platforms affected:
  All Operating Systems
  
  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 ADV

• Fixed component ID

  5737F35AP

Applicable component levels