We have an automated tape library.
I just check in tape cartridges in "scratch" status, and let ADSM pull
tapes as needed from the scratch pool into the backup and archive tape
pools.
My backup tape pool is colocated.
This works fine because I have more cartridges than clients.

But, we are about to add hundreds of clients, so that I will have more
clients than cartridges.
Each cartridge holds 35 GB, so I should be able to get several clients
per cartridge with no problem, but I would still like to colocate for
speed on restore..

How do other people handle this situation?
I think that probably all I have to do is stop using "scratch" tapes and
manually define a fixed number of cartidge volumes to each pool.  Are
there other considerations?