My organization is developing a DR "hotsite" at one of our other
facilities across town, and we are considering making some radical
changes to our TSM environment.  I know there are several folks on this
list that are heavy into TSM "design" and I could use all the input I
can get.

Our current environment consists of the following:
*       TSM server running 5.1.7.3 on AIX.  The server is a 6-processor
6H1 w/ 8GB RAM and four 2Gb HBAs.
*       Approximately 350 clients, and backup 1.5 TB nightly
*       We use a SAN-attached 3584 with 12 LTO-1 tape drives.  60-day
retention policy for everything, so we are maintaining ~90 TB in our
local and offsite (copypool) tape pools.
*       Disk storage pools, DB, Log, are all on SAN-attached IBM Shark
disk

Our objective is to take advantage of the hotsite not only to improve
our DR methods, but to improve TSM restore times.  This is what we're
considering:

*       Purchasing approximately 120-140 TB worth of SATA disk, which
will live at our current site.  All backup data will be retained on disk
which should improve restore performance.
*       Move the tape library to the hotsite, and install a second TSM
server there as well.  We would no longer create two tape copies of our
data, but we would create a single tape copy across town.
*       The two sites will be connected by dark fiber, so the speed at
which we can deliver the data to the 3584 should not be a problem.

Is anyone doing something similar to this?  Are there any major flaws
that I'm not considering?  Any advice and input is appreciated.

Also, I realize I need to go back and brush up on my TSM manuals, but
since I don't run a two-TSM server environment, I have forgotten exactly
how that will work in the kind of situation I describe.  Would I only
use the secondary server in the event of a disaster on the primary?  Or
would the secondary server at the hotsite manage the library? Etc?  If
someone can point me in the right direction on that aspect, I'd
appreciate it.

Thanks in advance,
Kevin