LTO tape drives SAN configuration usually involves tape drives, SAN switches, and server compoments(HBA etc..). Before putting them together, I suggest you take a bit time on support matric amoung them, this could save you a lot time in later diagnostics. 

I don't want to dig this part too much for usually Vendor will take care of it, but if you do have to check, here is a link you can use to have some quick check and ideas. Though it's for IBM supported products, most of popular products on the market are on the list:

http://www-03.ibm.com/systems/support/storage/ssic/interoperability.wss

Once hardware is setup and cables are connected, do the following steps. I'll mostly just show the LTO drives SAN configuration, for SAN switch and server side, I just give some ideas for they can't be easily covered in one article

1. Tape drives FC port setting

In most of cases, the drives comes with the library, by default, the drive ports are set to Auto link speed and topology Auto(L-Port)

L_port is the loose term used for any arbitrated loop port, NL_port or FL_port. Also known as Loop port.

Change the Fibre Channel Topology

 Change the Fibre Channel topology to point-to-point (N port), 
N_port is A Fibre Channel port in a fabric or point-to-point connection

Change the Fibre Channel Speed

 Change the Fibre Channel speed to the drives proper speed, for example: set 4Gbps for LTO4/5/6 drives, for non of these drives can reach that speed
 
 
 
 

SAN zoning

Login to SAN switch, creat SAN zoning for tape drives and servers

Host side setup

The setup on server may vary depends on HBA cards, tape device driver, library driver and application, but overall the list of things in below should be done properly.

1. HBA card and its firmware
2. HBA card driver
3. tape drive driver
4. The library driver
5. Application