My employer is in the early stages of planning for a move to a pair
of data centers. We are planning to have a TSM server at each data
center, with each server writing copy pool tapes on drives located
at the other data center. The TSM servers will run under either
mainframe Linux or AIX; we are still looking at the costs of the
two options. We have not picked physical locations yet, but our
selection criteria will probably lead to a distance between data
centers somewhere in the tens of kilometers.

I am aware of four options for extending FCP tape drive connections
over distances in this range: FCP over dedicated fibre, FCP over
shared fibre with wave division multiplexing, iFCP, and FCIP. I
gather that there are TSM sites with remote tape drives. Does
their experience offer strong reasons to favor or avoid
particular options?