Specifying stacked tape parameters for a copy request

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If you enabled tape stacking when you defined the basic copy request, you can set options that control when Tape Optimizer automatically loads new output tapes.

About this task

You can specify one or both of the following types of parameters:

  • The maximum number of files to load onto stacked tapes
  • Tape utilization thresholds by tape type

To enable the threshold levels, you must select the Start a new stacked tape when byte threshold reached option. Tape Optimizer will then automatically load a new output tape whenever a threshold level is reached. Consider setting threshold levels when you expect that the files on your input tapes will not fit onto one stacked tape and you do not want any of them to span multiple tapes.

If you specify both a maximum file count and tape-utilization thresholds, Tape Optimizer stacks data on a tape until the first of these limits is met and then loads a new tape. If you specify neither a maximum file count nor any threshold levels, Tape Optimizer uses the default maximum file count of 9999 to determine when to load a new tape.

RESTRICTION: If the source tape EXPDT is less than or equal to current day + 5 days, stacking output datasets will cause the EXPDT to be set to current day + 5 days, even though the input EXPDT is less.

To specify stacked tape parameters:

Procedure

  1. From the Tape Optimizer Primary Menu, choose option 2 (Copy Requests).
    The Copy Requests panel opens.
  2. Perform one of the following actions:
    • If you are defining a new copy request, type a forward slash (/) next to the Create a new tape copy request by VOLSER field or the Create a new tape copy request by data set name or mask field, and press Enter.
    • If you are editing a pending copy request, type a forward slash (/) in the Sel column next to the request, and press Enter.
    The Create/Edit Request panel opens.
  3. From the Options pull-down menu on the action bar, choose option 2 (Stack Options).
    The Stacked Tape Parameters window opens, as shown in the following figure:
    Figure 1. Stacked Tape Parameters pop-up window (for a copy request)
    +------------------------------------------------------------------------+
|      IBM Tivoli Tape Optimizer on z/OS - Stacked Tape Parameters       |
| COMMAND => __________________________________________________________  |
|                                                                        |
| Enter "/" to select option                                             |
|    _ Start a new stacked tape when byte threshold reached.             |
|                                                                        |
| Stacked tape media thresholds in megabytes                             |
|   18 track   200___          128 track   10000_                        |
|   36 track   400___          256 track   20000_                        |
|                              384 track   30000_                        |
|                              EFMT1       60000_                        |
|                              EFMT2       100000_                       |
|                                                                        |
| Specify maximum stacked tape file count  9999_                         |
|                                                                        |
| Specify Default Stacked Tape End Dataset Name Template:                |
|  TCMEND.D999______________________________                             |
|                                                                        |
| Enter END to save changes or CANCEL to return without saving.          |
+------------------------------------------------------------------------+
    Note: If you set default values for these options, the defaults are automatically displayed. You can accept or override them for the copy request.
  4. In the Start a new stacked tape when byte threshold reached field, type a forward slash (/) if you want Tape Optimizer to load a new tape in the output tape drive whenever the number of megabytes on an output tape reaches the threshold level that you specify for that tape type. Alternatively, clear this field if you want Tape Optimizer to stack tape data sets on the output tapes until the maximum stacked tape file count is reached.
  5. If you selected the Start a new stacked tape when byte threshold reached field, for each tape type under Stacked tape media thresholds in megabytes, specify the number of megabytes that must exist on an output tape to trigger the loading of a new tape.
    Either accept the default value or type another value that is within the valid range of values for the tape type. Valid values (in MBs) are:
    • 18-track tapes: 200 (default) through 600
    • 36-track tapes: 400 (default) through 2400
    • 128-track tapes: 10000 (default) through 60000
    • 256-track tapes: 20000 (default) through 120000
    • 384-track tapes: 30000 (default) through 180000
    • EFMT1 (enterprise recording format 1) tapes: 60000 (default) through 900000
    • EFMT2 (enterprise recording format 2) tapes: 100000 (default) through 1500000
    Tip: When setting threshold levels, consider whether data compression is being used and the degree of compression. Also, consider if the tapes are MEDIA3, MEDIA4, or MEDIA5 tapes. For MEDIA5 tapes, you should set a value for the EFMT1 or EFMT2 tape format.
  6. In the Specify maximum stacked tape file count field, type the maximum number of files that you want Tape Optimizer to place on a stacked tape.
    When the number of files on a stacked tape is one less than this maximum, Tape Optimizer will load a new output tape. Valid values are from 2 through 65535. If you do not specify a value, the default value of 9999 is used.
    Restriction: Do not specify a value greater than 9999 unless you use z/OS® 1.5 or later. Only systems with these z/OS versions support tapes that contain more than 9999 files. If you create stacked tapes that contain more than 9999 files, you might encounter problems when attempting to use these tapes on older z/OS systems.
  7. In the Specify Default Stacked Tape End Dataset Name Template field, specify a "template" for generating the name of the dummy data set that Tape Optimizer will record on a stacked tape for this copy request when either a tape media threshold or the maximum file count is reached and a new tape needs to be loaded.
    This data set name marks the end of a tape in the series of stacked tapes. The default value is TCMEND.D999. Tape Optimizer replaces "999" with a value that is composed of the characters 000-999 and AAA-FFF to ensure that a unique data set name is generated. You can add characters to the default value, if necessary, to create a template value up to 44 characters in length. The template value must start with “TCMEND” and end with “999.”
    Tip: Specify a template value that will generate unique data set names. Otherwise, if you use a RACF® TVTOC, the tape copy job will terminate abnormally.
  8. When you are finished, press F3 (End) to save your entries.
    The Create/Edit Request panel is redisplayed.