Hi TSMers,

I want to ask a more kind of general question for any recommendations

Currently we have one local tsm-server and a library with quite a lot capacity.
We want to backup another site being some hundreds km away with a good Gbit 
network
connectivity to our site. The remote site has about 200 clients with
a mixture of desktops,file-servers and so on - all 'normal' tsm clients.

Because an additional tape-library is not desired/needed there
seems to be 2 principally possibilities:

A) Placing a new tsm-server near by the clients at the remote site
   (acting as source server) having no library but a big disk-cache
   that may hold the backup-data of the last 4 weeks
   The next-stgs would be on our local site also on disk and
   finally migrating to tape.
   For this the setup of an additional logical tsm-Server
   acting as target server at the library-site is supposed.

B) Placing the new tsm-server nearby the library on the same
   machine - having direct access to the tapes.

So the questions is:
Are both possibilities not anomalous ?
Does one of those has a strong preference ? - any caveats ?
From network-view: is one solution much easier to handle  ?
     My thoughts on A) : Running long distances it seems to be easier to have 
the
     tsm-server nearby the client because only this has to be tuned
     to send/receive data from the library-link-node ... if it happens.
     On the other side : if the server is nearby the clients - this will
     lead to both short-distance client-connections and long-distance
     target-server connections. So here i am concerned about
     setting of the window-size of that tsm-server because it should be
     small for clients and at the same time high for the target server
     ... because of the so called long-fat-pipes
        - is this a problem ?
     on B) do all clients have to be tuned on the window-size ?

From tsm-view B) seems to be easier  -for example the use group-collocation-
From network-throughput the use of A) seems to be better because
data-transfers can be bundled and the transfer can be done when
its a good time to do so.

Last question is :
when using A)
is it a good idea or even perhaps 'a must' to make use of 'Cached Copy' ?
... or on the contrary is 'Cached Copy' something to avoid -especially
using virtual volumes ?


best regards
an thanks in advance for any hints !
Rainer