When adding a tape library to netvault the drives may not show up during the wizard. Even though the drives show up on Device Manager, proper licenses are in place and drives show up with nvscandrives.exe
Workaround:
Library can be added with empty bays. Then drives can be added through the nvlibrarymodify.exe
nvlibrarymodify.exe -servername "NETVAULTSERVER" -libraryname "NETVAULTSERVER: 10-0.7.1 (IBM 3573-TL)" -librarymachine "NETVAULTSERVER" -drivemachine "NETVAULTSERVER" -drivepath "11-0.7.0 (IBM ULT3580-HH6)" -add "DRIVE 2"
If there're doubts on the actual name from the library for this command, we can see it from Manage Devices or through the following command: