IC84946: HSM FOR WINDOWS NEW RECALL OPTION CONCURRENTTHREADLIMIT

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APAR status

  • Closed as program error.

Error description

  • New option in HSM for Windows to control the number of
    concurrent recall threads
    
    Problem Description:
    When an application is accessing a migrated file through a CIFS
    share, a system thread is utilized on the file server to send
    back the file content to the CIFS client. The system thread is
    blocked until the file is recalled by the HSM Recall service.
    Depending on the number of concurrent recalls and the time
    needed to recall each file, several system threads may be
    blocked at a time. Additionally, more than one system thread may
    wait for the same file, if multiple requests recalling the same
    file are issued. However the number of system threads is limited
    and depends on the operating system configuration and hardware.
    The file server might become unresponsive with a high number of
    blocked system threads until some or all files are recalled and
    the system threads are unblocked.
    
    Affected Products:
    HSM for Windows 5.5.x.x, 5.4.x.x, 6.1.0.0 - 6.1.5.0 (inclusive),
    6.3.0.0 - 6.3.0.1 (inclusive)
    
    Customer/L2 diagnostics (if applicable): No errors are reported
    by HSM for Windows, but file server is unresponsive for some
    period of time. Cluster environments may initiate failovers.
    
    Additional Keywords: HSM for Windows, Cluster failover
    
    Initial Impact: File server is hanging
    

Local fix

  • Increase the number of Windows system threads. Increase recall
    performance, e.g. by using more tape drives or using disk
    storage. Find out why that many recalls are initiated at once,
    reduce the number of concurrent recalls if possible. You can set
    HSM for windows recall option ConcurrentRecallLimit, IC72637
    (NEW HSM FOR WINDOWS RECALL OPTION CONCURRENTRECALLLIMIT)
    available in version 6.1.4.2 and later versions.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: TSM HSM for Windows Client Versions          *
    * 5.4.x.x, 5.5.x.x and 6.1.0.0 to 6.1.5.0 (inclusive),         *
    * 6.3.0.0 - 6.3.0.1 (inclusive)                                *
    *                                                              *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See ERROR DESCRIPTION                                        *
    ****************************************************************
    * RECOMMENDATION: Apply fixing level when available.           *
    * The new options are not available for versions 5.4.x.x and   *
    * 5.5.x.x.                                                     *
    ****************************************************************
    

Problem conclusion

  • PROBLEM CONCLUSION
    The new option ConcurrentThreadLimit has been implemented to
    control the maximum number of concurrently recalling Windows
    system threads. During recalls Windows system threads are
    blocked. Because the number of system threads is fixed the
    Windows system may become unresponsive.
    If a new recall request is initiated such that the number of
    concurrently recalling system threads exceeds the value of
    ConcurrentThreadLimit, the HSM for Windows filter driver will
    not initiate the recall of the file, but immediately return the
    recall request with an error. The error code can be configured
    with the option ConcurrentThreadLimitCode. The return code
    received by the application is the only indication that the
    ConcurrentThreadLimit might have been exceeded. No errors are
    logged by HSM for Windows.
    The value for ConcurrentThreadLimit applies to the total of all
    concurrently recalling system threads regardless of whether they
    were triggered through CIFS access or local file system access.
    This option is different from the configurable amount of
    concurrent connections of the HSM recall service (see
    http://publib.boulder.ibm.com/infocenter/tsminfo/v6/topic/com.
    ibm.itsm.hsmwin.doc/c_recall_stngs.html). This option is
    different from HSM for Windows recall option
    ConcurrentRecallLimit IC72637 (NEW HSM FOR WINDOWS RECALL OPTION
    CONCURRENTRECALLLIMIT), as one recall may block several Windows
    system threads waiting for the same stub file being recalled.
    
    In order to activate the concurrent thread limit the
    administrator has to manually create one DWORD value in the
    Windows registry under
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ithsmdrv
    \Parameters :
    Name:  ConcurrentThreadLimit
    Type:  REG_DWORD
    Value: Maximum number of allowed concurrent recall threads. The
    minimum value is "1" and the maximum value is 0x7FFFFFFF. If the
    option is not set, the maximum value is used. Every concurrent
    recall thread request exceeding this number is immediately
    returned with an error. The error code returned is by default
    0xC0000267 (STATUS_FILE_IS_OFFLINE).
    The system administrator can optionally change the error code by
    manually creating this DWORD value in the Windows registry at
    the same location:
    Name:  ConcurrentThreadLimitCode
    Type:  REG_DWORD
    Value: Error code returned to the application when
    ConcurrentThreadLimit is exceeded. If the option is not set, the
    default value of 0xC0000267 (STATUS_FILE_IS_OFFLINE) is
    returned. Consult with your Microsoft Windows system
    administrators or Microsoft Windows technical support before
    changing this value.
    After setting or changing any of these values the system must be
    rebooted in order to apply the changes.
    When the HSM file system filter driver recognizes and applies
    the registry value ConcurrentThreadLimit during boot time it
    reports feedback by writing the registry key
    ConcurrentThreadLimitStamp under
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ithsmdrv
    \Parameters :
    Name:  ConcurrentThreadLimitStamp
    Type:  REG_SZ
    Value: UTC date and time, maximum number of concurrent threads,
    return code for recalls that are denied due to the concurrent
    threads limit. (Sample: "12-06-18 08:33:42.062: 16,
    0xc0000267").
    If the HSM administrator or supporter recognizes this registry
    key he can be sure that the registry was configured correctly.
    
    Note: File access errors can occur for any number of reasons. It
    is possible for applications to receive 0xC0000267 for reasons
    other than exceeding the ConcurrentThreadLimit. It is also
    possible for applications to receive other file access return
    codes unrelated to ConcurrentThreadLimit.
    The error message presented to the user depends on how the
    application handles the error code to an error message.
    
    These options should not be applied or changed without thorough
    testing. The behavior of the applications receiving errors
    cannot be predicted nor controlled by HSM for Windows.
    HSM for Windows is not responsible for any application or
    operating system malfunction as result of applying these
    options.
    

Temporary fix

  • See LOCAL FIX
    

Comments

APAR Information

  • APAR number

    IC84946

  • Reported component name

    TSM HSM FOR WIN

  • Reported component ID

    5698ICNCL

  • Reported release

    610

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-06-28

  • Closed date

    2012-06-29

  • Last modified date

    2012-06-29

  • 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 HSM FOR WIN

  • Fixed component ID

    5698ICNCL

Applicable component levels

  • R610 PSY

       UP

  • R630 PSY

       UP



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Document information


More support for:

Tivoli Storage Manager HSM for Windows

Software version:

610

Reference #:

IC84946

Modified date:

2012-06-29

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