U disk boot disk made under Ubuntu system

An input terminal

sudo fdisk -l

See U disk path, such as / dev / sdb or / dev / SDC .

Then download the ISO file, such as file path /home/raina/xxx.iso

An input terminal

sudo dd if=/home/raina/xxx.iso of=/dev/sdb

Where if = back of the ISO file path, of = the path U disc
next write wait ISO file U disk (very slow)