IC72637: NEW HSM FOR WINDOWS RECALL OPTION CONCURRENTRECALLLIMIT

APAR status

• Closed as program error.

Error description

• New Option in HSM for Windows to control the Number of
  concurrent Recalls
  
  Problem Description:
  When an application is accessing a migrated file through a CIFS
  share, a system thread is started 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. 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:
  Tivoli Storage Manager HSM for Windows versions 5.4.x.x, 5.5.x.x
  and 6.1.0.0 to 6.1.4.0 (inclusive)
  
  Customer/L2 diagnostics (if applicable):
  No errors are reported by HSM for Windows, but file server is
  unresponsive for some period of time.
  
  Additional Keywords: HSM for Windows, system threads, freeze
  
  
  Initial Impact: File server is hanging
  

Local fix

• Increase recall performance, e.g. by using more tape drives or
  using disk storage.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: TSM HSM for Windows Client Versions          *
  * 5.4.x.x, 5.5.x.x and 6.1.0.0 to 6.1.4.0 (inclusive)          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See ERROR DESCRIPTION                                        *
  ****************************************************************
  * RECOMMENDATION: Apply fixing level when available. This      *
  *                 problem is currently projected to be fixed   *
  *                 in fixtest 6.1.4.1.                          *
  *                 The new options are not available for        *
  *                 versions 5.4 and 5.5.                        *
  ****************************************************************
  

Problem conclusion

• The new option ConcurrentRecallLimit has been implemented to
  control the maximum number of concurrent recalls and with that
  also the number of blocked system threads and waiting
  applications. If a new recall request is initiated such that the
  number of concurrent recalls exceeds the value of
  ConcurrentRecallLimit, 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 ConcurrentRecallLimitCode.
  The value for ConcurrentRecallLimit applies to the total of all
  concurrent recalls 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)
  
  In order to activate the concurrent recall limit the
  administrator has to manually create one DWORD value in the
  Windows registry under
  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ithsmdrv
  \Parameters :
  Name:  ConcurrentRecallLimit
  Type:  REG_DWORD
  Value: Maximum number of allowed concurrent recalls. 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
  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:  ConcurrentRecallLimitCode
  Type:  REG_DWORD
  Value: Error code returned to the application when
  ConcurrentRecallLimit 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.
  
  The return code received by the application is the only
  indication that the ConcurrentRecallLimit might have been
  exceeded. No errors are logged by HSM for Windows.
  
  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 ConcurrentRecallLimit. It is also
  possible for applications to receive other file access return
  codes unrelated to ConcurrentRecallLimit.
  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

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

• ithsmdrv
  

Fix information

• Fixed component name

  TSM HSM FOR WIN

• Fixed component ID

  5698ICNCL

Applicable component levels

• R610 PSY

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