Which JCL subparameter allows for mounting a multi-reel tape file onto the same physical drive?
Re: a jcl question
Posted: Thu Apr 21, 2011 6:05 pm
by Robert Sample
Look at UNIT=AFF
Re: mounting a multi-reel tape file
Posted: Thu Apr 21, 2011 9:03 pm
by steve-myers
I think Daimy Peter means to mount the tape volumes serially on one drive. This is the JCL and system default. For a multiple volume disk dataset, the system will "mount" all the volumes on multiple drives; it's been more than 30 years since removable disk drives were a common option.
Re: mounting a multi-reel tape file
Posted: Fri Apr 22, 2011 12:35 am
by NicC
Common description of UNIT=AFF: use the same tape unit for this DD as for that DD. For a dataset spanning multiple tape volumes the same unit is used for the next tape as for the previous. You cannot, as far as I know, mount volume 1 of 2 on one unit and volume 2 of 2 on another unit.
None of this is very desirable any more since most shops use virtual tape of some sort, tape library systems, or tape drive attachments to auto load tape volumes.