We ran option 1 for a long time both with twintailed scsi and a san but have
now mostly switched to option 2.  We shared all of the drives and frequently
ran into problems where tsmsvr1 had a drive and tsmsvr2 tried for awhile to
use it and then marked it unavailable until I marked it online.  With 1 you
definitely need different catagories and you have to be careful.  It makes
it easier if you use 100's for one and 200's for the other because I want to
say the number above the scratch is automatically saved for the same systems
private or vice versa and it can get you in trouble.  The best explaination
I have run into on how to set up the library manager is in the LTO Open
Redbook and you just modify what you need for 3494.

Good luck
Becky