sudo dd bs=4M if=/path/to/iso of=/dev/sdXX status=progress oflag=sync
$ sudo umount /dev/sdb1
$ sudo dd bs=4M if=/home/user/Downloads/ubuntu-18.04.2-live-server-amd64.iso of=/dev/sdb1 status=progress oflag=sync
sudo dd bs=4M if=/path/to/iso of=/dev/sdXX status=progress oflag=sync
$ sudo umount /dev/sdb1
$ sudo dd bs=4M if=/home/user/Downloads/ubuntu-18.04.2-live-server-amd64.iso of=/dev/sdb1 status=progress oflag=sync