DYNSTK

Whether the Control‑M/Tape Dynamic Dataset Stacking facility is activated.

• Mandatory

Valid values are:

• Y – Dynamic Dataset Stacking is activated. Default.
• N – Dynamic Dataset Stacking is not activated.

  Note: A matching rule must set DO STACK to YES to activate dynamic stacking for a specific request.

STKMODE

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

• Mandatory

Valid values are:

• S – Simple search. Searches for volumes from the same pool only. Data sets and volumes intended for vaulting are not eligible for stacking. Default.
• V – Searches for volumes from the same pool that have a vaulting pattern similar to the stacked data set. If the data set is to be vaulted, only volumes that have the same 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 for volumes from the same pool that have a similar or later retention date.

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

• A – Satisfies the requirements of both V and R.

  Note: This parameter was called DYNSTYP prior to version 5.1.4.

  This installation parameter determines the default stacking algorithm. This parameter can be overridden for data sets or groups of data sets using a DO STKMODE statement in a Control‑M/Tape rule.

STKTEST

Whether Dynamic Dataset stacking takes place while Control‑M/Tape is operating in Global TEST mode. Valid values are:

• Y – The Stacking facility is activated in all modes of operation (TEST, PHASED or PROD). Default.
• N – The Stacking facility is not activated when TEST is specified for the MODE parameter.

Note: The STKTEST parameter is ignored when the DYNSTK parameter is set to N. If STKTEST is set to Y, stacking decisions affect production environment decisions concerning the volumes to which data sets should be written when Control‑M/Tape is in Global Test mode.

STKSRCHL

The 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).

STKDEFSZ

Size in megabytes for the data set to be stacked. When a data set that is about to be stacked cannot be located in the Stacking Database, Control‑M/Tape references this parameter for the default data set size.

This parameter must be numeric and can have a 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.

STKKEEP

Whether data sets with a disposition of (NEW,KEEP) should be handled by the real-time data set stacking facility.

• Mandatory

Valid values are:

• Y – Stack data sets with a disposition of (NEW,KEEP) or (NEW,CATLG).
• N – Stack only data sets with a disposition of (NEW,CATLG). Default.

STKVNSPC

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

• Mandatory

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).

• Mandatory

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).

CTLGSCAN

Controls whether the Control-M/Tape Dynamic Stacking facility scans Catalog for the datasets in JCL. Valid values are:

• Y - Perform Catalog Scanning (Locate service) under Dynamic Stacking for the datasets in JCL. Default.
• N - Do not perform Catalog Scanning under Dynamic Stacking for the datasets in JCL.