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IT10833: STORAGE POOL MAINTENANCE PROCESSES MAY NOT WORK PROPERLY WHEN "SHOW DEDUPDEL" REPORTS A LARGE/GROWING QUEUE

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Storage pool maintenance processes like migration, reclamation,
    etc. may not work properly when the "SHOW DEDUPDEL" reports a
    large/growing queue with less or no activity in the worker
    threads, like:
    
    ANS8000I Server command: 'show dedupdeleteinfo'
     ****Dedup Deletion General Status****
     Number of worker threads          : 8
     Number of active worker threads   : 0
     Number of suspended workers       : 0
     Number of workers to suspend      : 0
     Number of chunks waiting in queue : 1900129737
    
        ****Dedup Deletion Worker Info****
        Worker thread 1 is not active
    
        Worker thread 2 is not active
    
        Worker thread 3 is not active
    
        Worker thread 4 is not active
    
        Worker thread 5 is not active
    
        Worker thread 6 is not active
    
        Worker thread 7 is not active
    
        Worker thread 8 is not active
    
        ------------------------------------------
        Total worker chunks queued     : 0
        Total worker chunks deleted    : 0
    
    The corresponding query actlog output may show the following:
    [...]
     ANR1000I Migration process 15246 started for storage pool
              STGPOOL automatically, highMig=20, lowMig=0,
              duration=None. (PROCESS: 15246)
     ANR1000I Migration process 15247 started for storage pool
              STGPOOL automatically, highMig=20, lowMig=0,
              duration=None. (PROCESS: 15247)
     ANR1000I Migration process 15248 started for storage pool
              STGPOOL automatically, highMig=20, lowMig=0,
              duration=None. (PROCESS: 15248)
     ANR1001I Migration process 15247 ended for storage pool
              STGPOOL. (PROCESS: 15247)
     ANR1001I Migration process 15248 ended for storage pool
              STGPOOL. (PROCESS: 15248)
     ANR1001I Migration process 15246 ended for storage pool
              STGPOOL. (PROCESS: 15246)
     ANR4935I Migration of primary storage pool STGPOOL has ended.
              Files migrated: 0,
              Bytes migrated: 0,
              Unreadable Files: 0.
    [...]
    
    The unique scenario here is that there are chunks with a
    non-null nodeid but have a null fsid. Due to this,
    the chunks are not getting assigned to any worker thread for
    deletion. As a result, the "not deleted" chunks stay on the
    volumes, occupy space in the stgpool and can't be moved.
    
    So if this SQL below many non-null nodeid's with null fsid's,
    this APAR would apply:
    
    db2 "select nodeid,fsid,count(*) from bf_dereferenced_chunks
    group by nodeid,fsid"
    
    NODEID      FSID        3
    ----------- ----------- -----------
            139           -   206880432
            141           -     1869010
            142           -     1828365
            143           -     1524678
            144           -   136568411
            146           -    59423697
            148           -   50532310
            150           -    21132853
            152           -    19503114
            156           -    33685989
    
    
    Tivoli Storage Manager Server Versions Affected:  6.3.x and
    7.1.x on all supported platforms
    
    
    Initial Impact: Medium
    
    Additional Keywords:  TSM dedup deletion chunks fsid nodeid
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All Tivoli Storage Manager server users.                     *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description.                                       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply fixing level when available.  This problem is          *
    * currently projected to be fixed in levels 6.3.6 and 7.1.4.   *
    * Note that this is subject to change at the discretion of     *
    * IBM.                                                         *
    ****************************************************************
    

Problem conclusion

  • The problem was fixed.
    Affected Platforms: AIX, HP-UX, Solaris, Linux, and Windows.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT10833

  • Reported component name

    TSM SERVER

  • Reported component ID

    5698ISMSV

  • Reported release

    63A

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-08-21

  • Closed date

    2015-09-15

  • Last modified date

    2015-09-15

  • 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

    TSM SERVER

  • Fixed component ID

    5698ISMSV

Applicable component levels

  • R63A PSY

       UP

  • R63H PSY

       UP

  • R63L PSY

       UP

  • R63S PSY

       UP

  • R63W PSY

       UP

  • R71A PSY

       UP

  • R71H PSY

       UP

  • R71L PSY

       UP

  • R71S PSY

       UP

  • R71W PSY

       UP



Document information

More support for: Tivoli Storage Manager

Software version: 63A

Reference #: IT10833

Modified date: 15 September 2015