Create tar backup on USB fails
Your USB stick probably uses the FAT filesystem, which has a maximum filesize of 4,294,967,295 bytes (4 GB – 1). To store bigger files, you either need to break them up (using something like split), or reformat the USB with another filesystem, like ext4, which can have larger files. A clean repartition might be best, tagging the recreated partition with the "linux file type 83, then format that with mke2fs or the tool of your choice.