DYNSTK

Determines whether the Control-M/Tape Dynamic Data Set Stacking Facility is activated. Specify Y (Yes) for this parameter.

STKMODE

Determines the search algorithm used by the Dynamic Data Set Stacking facility. The search is performed for each data set that is eligible for stacking to find the best matching volume. The selected search method influences both volume utilization and the resources required to search the Media Database for a matching volume.

Note: This parameter can be overridden for a specific data set or data sets through a DO STKMODE statement in a Control-M/Tape rule.

Valid values are:

• S—Simple search. Searches for volumes from the same pool only. Default.
  — Data sets that are to be vaulted are not stacked.
  — Data sets to be stacked are not placed on volumes that
      are vaulted or will be vaulted.
• V—Searches the same pool for volumes that have a vaulting pattern similar to the stacked data set. If the data set is to be vaulted, only volumes that have a matching vault pattern are considered. If the data set is not to be vaulted, only volumes that are not to be vaulted are considered.
• R—Searches the same pool for volumes that have a similar or later expiration date.

  Note: A permanent retention data set is stacked on a volume only if its last data set has permanent retention.

• A—Searches for volumes that satisfy the requirements of both V and R, above.

STKTEST

Determines whether stacking takes place while Control-M/Tape is operating in Global Test mode. If you are testing the Dynamic Data Set Stacking facility while in Global Test mode, set this parameter to Y; otherwise, specify N.

Note: Setting STKTEST to Y affects your production environment’s decisions regarding where (meaning, to which volume) a data set should be written while Control-M/Tape is operating in Global Test mode.

STKSRCHL

Maximum number of volumes to be searched for a stackable volume. This parameter must contain a numeric value from 0 through 9999. Default: 0 (no limit)

If the Dynamic Data Set Stacking facility searched the specified maximum number of volumes and did not find a suitable volume, the data set is written to a scratch volume.

Note: This parameter can be overridden for a specific data set or data sets through a DO STKSRCHL statement in a Control-M/Tape rule.

STKDEFSZ

When a data set about to be stacked cannot be located in the Stacking Database, Control-M/Tape references this parameter for a default size (in megabytes) for the data set.

This parameter must contain a numeric value from 0 through 99999. Default: 10.

Note: When STKDEFSZ is set to 0, no default is used. If the data set entry is not found in the Stacking Database, stacking is not performed for that data set.

You can override the STKDEFSZ installation parameter for a specific data set or data sets through a DO STKDEFSZ statement in a Control-M/Tape rule.

STKUNIT

Defines all unit names (as they appear in JCL) that are eligible for dynamic data set stacking. The format is:

STKUNIT=(unit1,unit2,.....)

Note: The STKUNIT installation parameter is ignored during handling of data sets managed by DFSMS. These data sets are considered stackable regardless of the unit name that is associated with them.

STKKEEP

Determines whether stacking takes place when DISP is set to (NEW,KEEP) for the data set. When STKKEEP is set to N, only data sets with DISP set to (NEW,CATLG) are stacked.

CTTMEDDF

Defines a Control-M/Tape logical media definition. This parameter is used to define a series of media attributes for each media type in use at the site. Relevant subparameters for the Dynamic Data Set Stacking facility are:

STKPCNT

Percentage of this media that can be filled up by dynamic stacking. This subparameter must contain a numeric value from 0 through 99.

CAPACITY

Media size (in megabytes). A value from 0 through 2047000000 can be specified.

For more information, see Step 2.11 of the Control-M/Tape installation in the INCONTROL for z/OS Installation Guide.

STKVNSPC

Determines whether Control-M/Tape selects volumes with non-specific retention for dynamic stacking.

Valid values are:

• N – Control-M/Tape does not select volumes with non-specific retention. Default.
• R – Control-M/Tape selects volumes with non-specific retention.
• V – Control-M/Tape selects volumes with vault retention set to UNTIL EXPIRED.
• A – Control-M/Tape selects volumes with either or both of the following:
• non-specific retention
• vault retention set to UNTIL EXPIRED

If you stack data sets on volumes with non-specific retention, Control-M/Tape stacks the data sets on the volumes according to the retention of the last data set on the volume, as follows:

• If the last data set is set to specific retention, the incoming data set is stacked on the volume if its retention period is shorter than that of the last data set on the volume.
• if the last data set on the volume has non-specific retention periods that have a statistical record, the incoming data set is stacked on the volume if its retention period is shorter than that of the last data set on the volume.

If the last data set on the volume has non-specific retention periods that do not have a statistical record, the volume is not used for stacking.

STKALCD

Whether the Control-M/Tape Dynamic Stacking facility is activated under Dynamic allocations (SVC 99). Valid values are:

• N – Do not perform Dynamic Stacking for data sets which are allocated by dynamic allocation (SVC 99). Only data sets allocated by DD cards in the JCL will be considered for Dynamic Stacking. Default.
• Y – Perform Dynamic Stacking for data sets which are allocated by dynamic allocation (SVC 99).