If reclaiming copy storage pool tapes which are marked as Offsite, the Move 
Data would utilize the data copy present on the in-library primary storage pool 
tapes.

Do the analysis of what's happening when your reclamation is running.  The more 
extreme the collocation, the more tape mounts will be involved, which 
aggravates elapsed time - which is why this "proxy" type of data copying is 
undesirable: returning offsite tapes for reclamation is preferable.  
Reclamation also has to contend for drives, and you can end up with thrashing 
where there is backup/restore activity needing drives.  Tapes which have not 
been stored under optimal conditions may be difficult to read, which you'll be 
able to perceive in Query Process showing no progress for a substantial period 
in copying data.  In some cases it's warranted to perform Delete Volume 
Discarddata=yes for ancient offsite tapes, with a high Reusedelay value to 
afford safety across a server event and to keep TSM mindful of the offsite 
tapes until they are returned onsite for ultimate reuse.

   Richard Sims