先格式化u 盤

假如u盤掛載在/media/disk上

解除安裝： sudo umount /media/disk 

格式化： sudo mkfs.vfat /dev/sdb

可以用 sudo fdisk -l檢視u盤是不是/dev/sdb。

不同的格式對應不同的格式化命令： mkfs mkfs.cramfs mkfs.ext3 mkfs.ext4dev mkfs.msdos mkfs.vfat  mkfs.bfs mkfs.ext2 mkfs.ext4 mkfs.minix mkfs.ntfs 

下載系統後用軟體刻錄到u盤上

Open the terminal and execute the following command to add repository.

sudo add-apt-repository universe

Execute the following command to add ppa.  Press Enter if being asked.

sudo add-apt-repository ppa:mkusb/ppa  # and press Enter

The following information will be displayed on the screen.

Figure 1:  Press “Enter” when being asked to add repository.

Execute the following command to update apt.

sudo apt-get update

Install the following two applications by executing the following commands:

sudo apt-get install -y mkusb-nox pv

Move to the directory in which the ISO file is stored.

cd /tmp

Tips:  ISO file can be downloaded from SFTP server, and the SFTP login credentials will be provided separately.  /tmp

Connect USB flash drive to computer and execute the following command to create a bootable USB flash drive.

sudo mkusb-nox  ./ubuntu-14.04.5-server-amd64-ygomi-custom.iso

Accept all the conditions when being asked.  It might take 20 minutes to install ISO file to USB flash drive.