TSM on Win2K is a good bet.  We've implemented a large cluster and it works
great.  Highly recommend attaching storage and tapes to fiber SAN as then
you can fail that over easily as well.

My feeling is that while Unix in general will probably outperform NT (read
the flames, etc., from previous discussions of this topic), HP-UX is
probably the orphan stepchild for TSM Server.  Just my feeling based on my
travels.  I've not seen many servers on this platform.

Win2K seems to have a much better IP stack and that stack appeared to be the
bottleneck on NT.

I also believe that mongo Intel hardware is getting real close to mongo Unix
hardware (now I know that Sun Big Iron and S70s are way different, but are
we talking about $200K boxes, or $50K boxes?) as far as performance and
costs go.  So for some environments, and perhaps even most (all but the very
largest sites) can be adequately served by TSM on Intel platforms.