Here are my thoughts:

Since this is a DR instance, all TSM data should be read-only.  With that said, 
you can restore the production TSM instance four times, so that you'll 
essentially have 4 identical TSM instances running.  Each TSM instance should 
have its own tape library.  Mark all copy volumes readonly or unavailable to 
start off with.

To determine which tapes should go where, you can run off of one instance and 
run volumeusage or content selects for specific DR nodes.  That'll get you a 
tape list and you can more accurately load/checkin tapes to balance the 
restores across all 4 instances.  Since these tapes probably aren't collocated, 
there will inevitably be some tape swapping between libraries, but at least 
you'll be able to run restores off of 4 drives and you'll minimize the number 
of tape swaps you'll need to do (if you balanced correctly).  Invariably, 
you'll be doing some amount of tape swaps, so maybe your just better off 
running the one instance with manual drives.  Oh well, I tried.

HTH,
Sergio

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Wanda Prather
Sent: Thursday, July 09, 2009 9:34 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] Desperation, DR, and four TS3100 libraries...

I'm drawing a blank here, any suggestions welcomed.

I have a TSM customer who makes their copypool tapes using a TS3200 with
LTO4 drives.
The TS3200 is a rack-mounted, 2 drive, 40-mumble slot standard ASCII
library.  No issues.
One copy pool, tapes vaulted and sent offsite.

They want to go to a commercial DR vendor site and do a DR test next week.
The commercial DR vendor, unbelievably, has no multi-drive LTO4-capable
libraries.

Instead, they want us to use 4 (count 'em, four) TS3100 libraries.
The TS3100 is a rack-mounted, 1 drive, 20-mumble slot standard ASCII
library.

There's only 1 copy pool, so all tapes were created on the same device
class.
Ignoring the which-carts-would-go-in-which-library issue, I can't have a
device class pointing to 4 libraries.

And, the TS3100 is built in such a way that unlike a TS3500, you can't open
the doors and access the drives for manual mounting.
(I'd be happy to pull the covers off and try it, ignoring any warranties I
might void, but I doubt the vendor will let me attack the thing with a
screwdriver/wrench/hacksaw.)

If I put all the carts in one TS3100 that will work, but that leaves me only
1 drive to restore all the clients, and they won't likely get done in the
desired time window.

The only thing I can think of to use all 4 drives, is to define those four
TS3100's as 1 manual library with 4 manual drives, and use the front panel
of each TS3100 to move tapes from the I/O slot to the drive when TSM
requests a mount.

(Actually the FIRST thing I thought of, was "cancel the DR contract, this is
nonsense".  But my customer isn't convinced yet...)

Anybody got a better solution?
I've already tried a margarita, it didn't help....

W