I think I am right in syaing that as a tape is essentially a streaming device it does not have a file system as such and cannot therefore be formatted. To erase a tape however, use the all flavours of 'IX command 'mt erase' (see man mt). You will need the device name of your SCSI tape drive . It is a very long time since I used a tape drive so I am a bit rusty on the details.
