Helo.
First of all, I'm not an expert in backup but here the experts have configured a script that, everytime the TSM server reboots, configures the tapes. It basically deletes the tape devices and then, hba by hba, configures them again, changing "alt_pathing" into "yes" when appropriate. This process, I think, depends on your configuration and must be mantained by hand.
I hope this helps.
Regards.