If you want to collocate existing, non-collocated data it is not necessary to
back up the files again.  You
can use either  reclamation or Move Data to transfer the files from the volumes
on which they currently
reside to new, collocated volumes within the same sequential-access storage
pool.

However, transferring data directly from a non-collocated tape to a set of
collocated tapes can be very inefficient
because the files are grouped by node/filespace to minimize mounts of the
target media while still ensuring
collocation of that media.  If you have a lot of data to transfer and can
afford the disk space, it is usually much
faster to move data from the non-collocated tape to a disk pool and then let
the data migrate from there back
to the tape pool.

Dave Cannon
ADSM Development