IBM Support

IT28470: DELETION OF EXTENTS IS NOT REDUCING

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APAR status

  • Closed as program error.

Error description

  • The deletion of extents from a directory container pool can be
    inefficient and at times may appear not to remove extents at
    all.
    
    The QUERY EXTENTUPDATES command provides the number of extents
    which are queued for deletion by the deletion engine thread.
    Example output  :
    
    
    Number of Extents Not Referenced
    
    ---------------------------------
    323,656,906
    
    
    Number of Extents Eligible for
    Deletion
    ------------------------------
    320,149,903
    
    
    The number of extents eligible for deletion should reduce over
    time and is the responsibility of the background deletion worker
    threads.  This then frees the space back to the container pool.
    If the number of extents eligible for removal is not reducing or
    even seems to grow, this issue is being encountered.
    
    The cause of the issue, is that the same container can be added
    to the queue several times to spread the work of extents to the
    deletion worker threads. The worker threads can spend a lot
    of time examining the same container for extents which may now
    no longer exist if other threads have removed extents and the
    container itself.
    
    
    Customer/L2 Diagnostics (If Applicable)
    
    
    IBM Spectrum Protect Versions Affected:
    Spectrum Protect Server versions 7.1.x and 8.1.x on all
    platforms.
    
    Initial Impact:
    Medium
    
    Additional Keywords:
    TSM, TS001890294, ANR0522W, space, freed, directory
    

Local fix

  • Recycle the server instance, which rebuilds the list of extents
    to be removed and set the following option :
    
    setopt ChunkDeletionDelay 300
    
    The above option controls how often containers are examined for
    eligible chunks and placed on the queue. The default is 30
    seconds, so changing this to 300 seconds reduces the chance of
    the same container being placed on the queue
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All IBM Spectrum Protect server users.                       *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * All IBM Spectrum Protect server users.                       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply fixing level when available. This problem is currently *
    * projected to be fixed in levels 8.1.6.200, 8.1.7.100 and     *
    * 8.1.8. Note that this is subject to change at the discretion *
    * of IBM.                                                      *
    ****************************************************************
    

Problem conclusion

  • This problem was fixed.
    Affected platforms for reported release:  AIX, Linux, and
    Windows.
    Platforms fixed:  AIX, Linux, and Windows.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT28470

  • Reported component name

    TSM SERVER

  • Reported component ID

    5698ISMSV

  • Reported release

    81W

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-03-15

  • Closed date

    2019-04-16

  • Last modified date

    2019-04-16

  • 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

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSGSG7","label":"Tivoli Storage Manager"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"81W","Edition":""}]

Document Information

Modified date:
16 April 2019