About the situation of only reclamating one tape at a time.
You could setup disk space for FILE sets and reclaimate from tape to disk.
(I.E. the one tapedrive reclamation recommendations but using 2 or more
 tape drives and disk spaces.)  Maybe?  I have not tried this to see
if ADSM with 'cooperate'  ... :-)   But I am doing 1 drive reclamation.

                          joe.f.

> We in fact have DLTs, and the way we address this is twofold.  First, we
> have lots of DLT drive (8) and we run multiple migration processes
> (migproc=3 or 4).  However, your point has validity to it.  The situation
> we run into is that only 1 reclaim can run at a time, and I do have a
> concern about whether the reclaim activity can keep up with the incoming
> data.  Secondly, we have increased the amount of disk space fronting the
> tape storage pools.  Since the collocation algorithm move largest filespace
> first, this means that each subsequent filespace will be smaller and
> smaller, with diminishing returns per tape mount.  Adding disk allows us to
> cut back on the number of tape mounts somewhat.
>
> I believe that collocation needs to be improved, but I am uncertain what a
> requirement would look like.  I do know that we *require* collocation,
> because the alternative of not using it would not work for us - restores
> would take far too long.  I would think this would be a problem even with
> non-DLT solutions, even though the mount waits would be shorter - at least
> in large libraries.
>
> If you do use collocation, as Steve points out, it is important to keep a
> sufficient number of writeable empty or filling tapes, or else the
> collocation algorithm will devolve into a non-collocated result.  We have
> seen this happen as the capacity of our tape library is reached.
>
> ..Paul
>