IT37839: PARTIAL FILE RECALL DOES NOT CREATE STUB FILES SMALLER THAN 10MB

APAR status

• Closed as new function.

Error description

• IBM Spectrum Protect for Space Management's partial file recall
  function uses an undocumented 10MB minimum block size for all
  partial file recall operations.
  
  
  This includes selective or "dsmrecall -offset -size" command
  based or transparent. This setting can be adjusted to the lowest
  multiple of filesystem block size that is higher than 10MB.
  
  
  
  Customer/Support Diagnostics (If Applicable):
  
  
  Spectrum Protect Versions Affected:
  All versions on all supported platforms
  
  
  Initial Impact:
  Low
  
  
  Additional Keywords: (please include the case number in any
  case)
  TS006251735, partial file recall, block size, minimum, 10MB
  

Local fix

• This is a work around. The dsmrecall creates a large stub file
  (the lowest multiple of filesystem block size that is higher
  than 10MB) once, but dsmmigrate updates it to 4194304 bytes in
  this example.
  "/hsm_fs" and "file" under "/hsm_fs" are examples.
  
  To make sure all migrated files have one fs block (e.g. 4194304
  bytes) of resident file data:
  dsmmigfs update -STUBSize=4194304 /hsm_fs
  
  For each "file" on "/hsm_fs":
    dsmattr -recall=partial /hsm_fs/file
    dsmrecall -offset=0 -size=4M /hsm_fs/file
    dsmmigrate /hsm_fs/file
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * IBM Spectrum Protect for Space Management (HSM) client       *
  * versions 7.1.x and 8.1.x on AIX GPFS and Linux GPFS          *
  * platforms                                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See ERROR DESCRIPTION.                                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply fixing level when available. This problem is projected *
  * to be fixed in IBM Spectrum Protect for Space Management     *
  * (HSM) client level 8.1.13. Note that this is subject to      *
  * change at the discretion of IBM.                             *
  ****************************************************************
  

Problem conclusion

• Before the fix, the IBM Spectrum Protect for Space Management
  (HSM) client partial recall (PFR) function recalled 10M file
  data block at the minimum.
  After the fix, the default minimum PFR block size will match the
  file system block size.
  For example, for a 100M migrated file located on a file system
  with 4M file system block size, the actual size that is recalled
  by "dsmrecall -offset=0 -size=4M":
  - (before the fix), the actual size is 12M.
  - (after the fix), the actual size is 4M.
  Note: in any case, the actual size value is rounded up to a
  multiple of the file system block size.
  

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:

Modules/Macros

• dsmc
  

Fix information

• Fixed component name

  TSM SPACE MGMT

• Fixed component ID

  5698HSMCL

Applicable component levels