I have almost same issue as https://www-secure.symantec.com/connect/forums/netbackup-75-library-configuration.
I have Oracle SL150 Tape Library connected through Fiber. I have netbackup 126.96.36.199 installed on Solaris 11.1 (x86). I can see the only Tape Drive and unable to see the robotic (media changer). I have rebuilded sg driver many times ,but no success. some body help in this regard.
In Solaris x86, the OS multipathing must be disabled.
Extract from Device Config Guide:
I also am faced with NetBackup 188.8.131.52 not seeing the FC connected tape library or drives under Solaris 11.1. The OS can see the tape drives. The library connection piggy backs on one of the tape drive fc links. I have run the 'sg.build all' and 'sg.install' scripts but the results are not successful. Strangely, the sg.conf file located at /kernel/drv does not change to the new one created by the sg.build script. The date is correct on the file but it does not contain any of the wwn information. Any help is greatly appreciated.
Truncated cfgadm output: