IJ50563: STALE DATA OF FILES WITH NUMBER OF DATA BLOCKS MORE THAN 5000 MIGHT NOT BE REPAIRED DURING DISK START PROCESS WITH MMCHDISK

APAR status

• Closed as program error.

Error description

• In a file system with replication configured, for a large file
  with number of data blocks more than 5000, if there are
  miss-updated on some data blocks\ due to disk failures on one
  replica disk, then these stale replicas would not be repaired if
  the helper nodes are getting involved to repair them.
  

Local fix

• Only specify the fs mgr node as the participant node for
  mmchdisk command.
  

Problem summary

• In a file system with replication configured, for a large file
  with number of data blocks more than 5000, if there are
  miss-updated on some data blocks\ due to disk failures on one
  replica disk, then these stale replicas would not be repaired if
  the helper nodes are getting involved to repair them.
  

Problem conclusion

• This problem is fixed in 5.1.9.3
  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:
  Avoid the stale replicas to be missing repaired on large files.
  
  Work Around:
  Only specify the fs mgr node as the participant node for
  mmchdisk command.
  
  Problem trigger:
  I/O errors on disk caused it marked as "down", and some further
  write failures happen on a large file with the number of data
  blocks more than 5000, then start the down disk with multiple
  participant nodes.
  
  Symptom:
  replica mismatch
  
  Platforms affected:
  All Operating Systems
  
  Functional Area affected:
  Scale Users
  
  Customer Impact:
  Critical
  

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