I noticed that TSM is unable to handle the redundant path to the tape library. As the path to the library is hardcoded in the configuration something like:
def libr TS3500 libtype=SCSI
def path TSMServer TS3500 srct=server destt=library device=lb4.1.0.5
But if you are lucky, the path failover can be handled by the device drivers. In my case, I use one of the IBM TS series tape drive which is in the supporting list.
There are two types of path failover: DPF and CPF. DPF stands for Data Path Failover, which provides error recovery for system connected tape drives. CPF stands for Control Path Failover, which is an automatic failover support for the transfer of command to move tape cartridge.
The DPF and CPF can be enabled or disabled by importing the relevant registry file which is in the reg folder.
Reference:
Jackie Chen's IT Workshop 
Hi Jackie
Where to check FC code for tape libraires to use CPF , DPF , any links ?
Thanks
Shyam
Refer the installation guide. The link can be found at the bottom of my post.