Why does FMP for IMS create a few log datasets in VIO format, Instead of DA Dataset.

Document ID : KB000014057
Last Modified Date : 14/02/2018
Show Technical Document Details
Introduction:

Using File Master Plus for IMS V10. 

Question:

Why does FMP for IMS create a few log datasets in VIO format, Instead of DA Dataset?

Environment:
Running File Master Plus for IMS V10
Answer:

The allocation is performed by the Rexx dialog that starts the editor using a TSO ALLOCATE command.

If Volume serial & Unit are both unspecified the allocation is attempted against the SYSDA unit name.

If either the Volume or Unit is specified the allocation is attempted against the specified volume or the specified Unit.


2. Depending on the Change Log option the Change Log data set may be allocated new or re-alllocated.

3. the ONL_CLOGFOR, ONL_CLODSN and CLOGSPA options in the CAWKOPT table of options may enforce
- The Change log data set name syntax
- The Primary and Secondary space values with the Primary space not 0 forcing the use of a Change Log data set in every Edit session.

Hopefully these pieces of information will help you to determine the conditions in which the Change log data set is allocatied on a VIO unit.

- Check out the CAWKOPT table
- Check out the IMS environment définitions.

For any suspcious IMS environment you may try the TSO ALLOCATE command in a standalone Rexx and verify where the data set was allocated.

The product never requests an allocation of the Change Log data set on a VIO explicitly.