1. Run fdisk /dev/sdb
2. Create a new partition table with ‘o’
3. Create a new partition with ‘n’
4. Let it use the default values by hitting ENTER when it asks for numbers, to take the entire available disk in this partition
5. Write the new partition table with ‘w’, which should dump you back to the prompt.
6. Finally, you should have a /dev/sdb1 to format using the following command:
sudo mkfs.vfat -n ‘Ubuntu’ -I /dev/sdb1