How to create a bootable USB stick on OS X

We would encourage Mac users to download Ubuntu Desktop Edition by burning a CD. But if you prefer to use a USB stick, please follow the instructions below.

Note: this procedure requires that you create an .img file from the .iso file you download.

提示： Drag and drop a file from Finder to Terminal to 'paste' the full path without risking typing errors.

1

下载Ubuntu桌面版
2

Open the Terminal (in /Applications/Utilities/ or query Terminal in Spotlight).
3

Convert the .iso file to .img using the convert option of hdiutil (e.g.,hdiutil convert -format UDRW -o ~/path/to/target.img ~/path/to/ubuntu.iso)

Note: OS X tends to put the .dmg ending on the output file automatically.
4

Run diskutil list to get the current list of devices.
5

Insert your flash media.
6

Run diskutil list again and determine the device node assigned to your flash media (e.g. /dev/disk2).
7

Run diskutil unmountDisk /dev/diskN (replace N with the disk number from the last command; in the previous example, N would be 2).
8
Execute sudo dd if=/path/to/downloaded.img of=/dev/rdiskN bs=1m (replace /path/to/downloaded.img with the path where the image file is located; for example, ./ubuntu.imgor ./ubuntu.dmg).
- Using /dev/rdisk instead of /dev/disk may be faster
- If you see the error dd: Invalid number '1m', you are using GNU dd. Use the same command but replace bs=1m with bs=1M
- If you see the error dd: /dev/diskN: Resource busy, make sure the disk is not in use. Start the 'Disk Utility.app' and unmount (don't eject) the drive
9

Run diskutil eject /dev/diskN and remove your flash media when the command completes.
10

Restart your Mac and press alt/option key while the Mac is restarting to choose the USB stick.