Get the smaller USB drive you have. Format it in ext4
or smater.
Mount it on /mnt/usb
.
Then
$ cd /mnt/usb
$ dd if=/dev/urandom of=sparse-file bs=1k seek=10737418240 count=1
$ ls -lha sparse-file
-rw-rw-r-- 1 gawen gawen 11T Nov 15 19:25 sparse-file
$ df -h /mnt/usb
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 8G 4K 8G 0% /mnt/usb
11T
of file, 4K
used.
TADAAA!