Yes, there are a few cases where ADSM will need to start an
additional "filling" collocation volumes.  One obvious case is when
reclamation and migration are running at the same time.  If reclamation
is writting to an output volume that migration also wants to write to,
the migration process won't wait around for it.  Instead it will choose
a new tape.  There is also another case involving reclamation and files
that span across tapes, when it will possiblity create another "filling"
volume.

Apar PN79990 is important.  In the past ADSM would not ask for these
other filling tapes for a long time or ever.  It looks like this fix
was in PTF 7 for the version 2 server.

Dave Crockett - ADSM development