I want to install Ubuntu onto a USB drive and boot into an actual installation of Ubuntu using my MacBook Air, but I'm not sure if this is possible. To clarify, I don't want to install a live version of Ubuntu, with or without persistent storage. I want to use the USB drive as if it were a drive attached to the computer, and I were booting into another fully-installed OS, with the USB drive functioning as the hard drive for that OS. I have read some things about installing Ubuntu on a Mac, and some things about installing a live version on a USB drive (with or without persistent storage), none of these things are exactly what I want to do. -- And, in fact, I did already try installing a live version on a USB drive, but it didn't work properly for some reason. It would boot into Ubuntu and run, but then the graphics would start to get all messed up (I had some issues with things being entirely blacked-out, and one time, the whole screen just went black and stayed that way). I'm not sure if what I want to do is possible, but if it is, or if there are any other ideas anyone has, I'd really appreciate it! I miss Ubuntu so much, and really want to be able to actually use it again. <3

Thank you for any help you can provide!


Fairly straightforward and courtesy of ubuntu.com:

  1. Download Ubuntu Desktop
  2. Open OS X Terminal
  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, like /dev/disk2
  7. Run diskutil unmountDisk /dev/diskN replacing 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 replacing /path/to/downloaded.img with the path where the image file is located, e.g., ./ubuntu.img or ./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.
  • Thank you! I did try this before I asked this question, I just wasn't clear on whether this actually utilized the USB drive such that I could install software, or create files on the Ubuntu installation that would stay as-is after reboot. Is that the case? There wasn't any more detailed information on this on the instructions page. Thank you again for replying! – J.D. Sep 5 '15 at 19:08
  • Yes, that should absolutely be the case. Make sure you start out with a sufficiently large USB drive based on your needs. Personally, I'd start with at least 4GB and probably 16 or more. But that is dependent on your use case. – SaxDaddy Sep 6 '15 at 5:29
  • I tried it and it booted from the flash drive as a live distro that I could choose to either use or install. It wasn't actually installed onto the flash drive. There was also some serious issue with the GUI because the controls weren't displaying text or graphic correctly -- I had this problem when booting into a live distro previously. I'm going to try to install Ubuntu onto the flash drive maybe through booting into a live Ubuntu disk using VirtualBox, and using the flash drive as the target hard drive. Maybe that will allow me to use the flash drive as the installation location... – J.D. Sep 10 '15 at 3:18

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