II13604: SLOW VTS SCRATCH MOUNTS IF FAST READY NOT SET AFTER PARTITIONING

APAR status

• Closed as canceled.

Error description

• When using the DEVSUPxx Parmlib member to set new categories to
  partition a VTS tape library, insure that the new categories
  have the Fast Ready attribute set at the VTS Library Manager.
  Example SYSA SYS1.PARMLIB(DEVSUP00):
  volnsns=yes,
  compact=yes,
  media1=0011,
  media2=0012,
  media3=0013,
  media4=0014,
  error=001E,
  private=001F
  .
  Example SYSB SYS1.PARMLIB(DEVSUP00):
  volnsns=yes,
  compact=yes,
  media1=0021,
  media2=0022,
  media3=0023,
  media4=0024,
  error=002E,
  private=002F
  .
  Any valid scratch categories for the VTS should have the Fast
  Ready Attribute set at the library manager.  Typically this
  would be the media2 categories, but could also be media1 and
  possibly others in the future.  In the example, 0012 and
  0022 should have Fast Ready set at the VTS.  Refer to the IBM
  TotalStorage Enterprise Automated Tape Library (3494) Operator
  Guide (for example: GA32-0449-00) in the section titled "Define
  Fast Ready Categories" for details on how to do this from the
  VTS Library Manager PC.
  .
  If Fast ready is not set up for the new scratch categories,
  the VTS will think it has to recall the complete logical volume
  for the selected volume from the VTS physical stacked volume,
  which can cause a much longer mount time if the logical volume
  is not in the tape volume cache.
  .
  Other notes on partitioning:
  From the OAM PISA for Tape Libraries ( SC35-0427-02 )
  Processing Default Categories When Using DEVSUPxx in an ATLDS:
  If an installation has been running with its tape libraries in
  unpartitioned mode for some period of time, the tape volumes
  will already be assigned to default categories. When the
  partitioning related DEVSUPxx parameters are used, special
  processing is necessary to move volumes to the new categories
  established through DEVSUPxx:
  .
  - Modify the DEVSUPxx PARMLIB member associated with each system
    or sysplex, or both, in each TCDBplex.
  - IPL all systems in the TCDBplex to activate the DEVSUPxx
    changes.
  - Ensure that no jobs which require scratch mounts in a library
    are run. This may be done by varying all library-resident tape
    drives offline to all systems.
  - Start the OAM address space and make sure that all tape
    libraries are online. The tape drives must remain offline.
  - Obtain a list of volumes whose storage group name is *SCRTCH*
    using the ISMF Mountable Tape Volume Application. It is a good
    idea to do this one library at a time by also specifying the
    library name.
  - Use the ISMF ALTER command (not the line operator) to change
    the volume use attribute for all volumes in the list from
    scratch to scratch. This causes the library manager category
    for each volume to be changed from the default value to the
    new value established through DEVSUPxx. All volumes in the
    default scratch categories and in the error category are
    changed to the new DEVSUPxx scratch categories.
  - It is not necessary to change the category of private volumes.
    When a private volume is returned to scratch, its category
    will be changed to one of the new scratch categories.
  - Vary the tape drives online as appropriate, and start to run
    normal tape job streams.
  .
  From SG24-4409-02
  Guide to Sharing and Partitioning
  IBM Tape Library Dataservers
  .
  Fast-Ready Attribute for Categories
  With the introduction of the Virtual Tape Server, an attribute
  can be assigned to a category that allows the Storage Management
  Software in the Virtual Tape Server to know that it can use the
  last usage information maintained in the Tape Volume Cache to
  process a nonspecific mount instead of having to recall the
  complete logical volume for the selected volume from a Magstar
  cartridge. The attribute for a specific category is set by the
  operator through a panel on the Library manager.
  .
  B.20.8 Define Fast-Ready Categories
  To take advantage of the scratch-mount performance advantages of
  the Virtual Tape Server, as described in Section B.16, “Scratch
  Mount Scenario” on page 219, you need to indicate to the Library
  Manager the numbers of the categories used by the host for
  scratch volumes. You do this through the Library Manage console.
  The Library Manager provides a panel by which a 4-digit category
  number can entered. This will add the category to the list of
  categories in the library that have the Fast-Ready attribute
  set.  To reset a category's Fast-Ready attribute, the Library
  Manager panel allows you to highlight one of the categories in
  the list with the Fast-Ready attribute set and then request that
  it be reset.
  

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

•  Info Apar
  

APAR Information

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Fix information

Applicable component levels