A customer of mine  is working on a full LPAR copy scenario but frequently many VSAMs (Cics, db2 and so on ) are migrated to tape and therefore
the resulting  ZD&T environment always lacks something and it's not simple to find what is missing on teh ZD&T environment.
This problem makes the zdt environment almost unusable.

QUESTION: In addition to asking the customer to dis-archive the objects as much as possible before to start a full lpar copy ( an option that can be very expensive for the customer
in terms of space usage)  there is someone that can suggest a more efficient way to solve the problem?

I've seen the redbook seems to refer at least to 2 possible scenarios

1) attach the device directly to the ZD&T ( see appendix 1)
2) use the scsi2tape command , in order to copy the tape volumes to a linux file (see appendix2 )

.. but I've not experience in this field  so I'm not sure the above approaches can solve the problem

many thanks in advance

Appendix1 ( from ZPDT redbook, chapoter 14.3 zPDT 359x Tape Support) 

(ITC6 has worked with zPDT development by testing changes to the awsscsi device manager
that are designed to more fully support FCP attached IBM 3590/3592 tape units. Although these devices could be physically attached to a zPDT system prior to these awsscsi
enhancements, they functioned only in a rather basic mode, emulating a 3490 device. The updated support allows these units to operate in full 359x mode, with minor exceptions.7
All tests were run using openSUSE 12.2 and the Xfce user interface/desktop. The base zPDT system was driver 45.18 and the AWSSCSI modifications were applied on top of that
release. Other versions or flavors of Linux were not tested and results may be unpredictable).

Appendix2 ( from ZD&T redbook 4.1.43 The scsi2tape command)
The scsi2tape command copies a tape volume (mounted on a SCSI tape drive) to a Linux file
in awstape format. Linux files in awstape format may be managed and read (by the awstape
device manager) as though they were tape volumes on a real tape drive. zPDT does not need
to be running to use this command.

HI Giuseppe, 

Attaching a tape device to your Linux may not solve your lack of data. Tape devices in general are not actually tapes any more, they are in general disks emulating tapes.

The strategy to use zD&T effectiveness would be to select the datasets related to specific application and move only what you need. Avoid to move too much data. In a real system all application are integrated, but their data can be isolated. Eventually, you can select more than one application that are tightly integrated, but we discourage to move all disk space. If you consider also to move some tape space, it will be make zD&T not feasible. 

If the data sets are SMS managed, when you refer to them an automatic RECALL will be started and the dataset will be restored in disk spaces. So, you should not need to worry about data in tapes. If the data is archived, it can be restored and work in the same way as migrated.