Attempting to incorporate a MERGE function to free up tapes for the Scratch pool.
Refer to the Disk Systems Guide for the Sysparm DYNTUNIT. In that description there is a table of about 30 values relating to various tape types and capacity.
So, to get the estimated number of new tapes that Merge would create, perform the following:
Specify SIMULATE for the MERGE command.
//SYSPARMS DD *
DYNTUNIT34906
As an example, for 3490/E 60 GB capacity tapes.