TMC fields BLKSIZE and BLKCNT are not populated

Products

• VM:Tape for z/VM

Issue/Introduction

TMC fields BLKSIZE and BLKCNT are not populated for tapes created on z/VM by VM:Backup, HiDRO and VM:Archiver.

These fields have a value of zero.  Is it possible to enable the fields to be populated? 

Environment

Release: VMTAPE55400-2-VM:Tape
Component:

Resolution

Tapes created by VM:Backup, HiDRO and VM:Archiver do not populate the BLKCNT and BLKSIZE fields when they write data to tapes managed by VM:Tape. Those fields do get populated in z/OS though.   No matter what type of TMC it is, CMS does not provide facilities for capturing block counts, block sizes and VM:Tape does not maintain them.

Additional Information

You may want to consider implementing VM:Tape's USERACNT user exit which is called by the MOUNT command and will initialize or modify local site-defined fields in the accounting area of the TMC record.  The accounting area is field ACCT and is 50 bytes long.