I see this issue reported a lot but all the accepted solutions have not worked for me.

I have created a bootable USB stick using UNetbootin with a Debian image. The USB stick is FAT32 formatted with a GUID partition table.

When I reboot with the usb stick plugged in and hold down option I'm only presented with the MacOS hard drive to boot from.

I've successfully reset the PRAM using option+cmd+p+r keys but this has had no effect.

I've not found any other suggested solutions to the problem. What am I doing wrong?

  • You're really going to have to tell us what you tried & what happened when you did; otherwise we're just going to present the same solutions again. Also, for future ref; blowing the PRAM almost never 'fixes things'. – Tetsujin Apr 26 '18 at 10:04
  • That is everything I've tried. The solutions I've read elsewhere amount to checking the usb is FAT 32 formatted with a GUID partition table and to reset the PRAM. The result was no effect - still no usb drive option in the boot menu. – Sio Apr 26 '18 at 10:07

If you have succesfully made a bootable linux USB stck before with your method, try a different USB stick or image. It sounds like you have done this before, which suggests perhaps that the image is not right in some way.

A GUID partition table and FAT format are correct.

Other things to try:

1. Try Etcher: It's simple and free. You can find a tutorial from Ubuntu regarding making a bootable Ubuntu drive with it, but all it really says is "use Etcher."

2. Try Mac Linux USB Loader. It costs ~ $5, and while it only supports certain OSes, Ubuntu is one, so Debian probably works.

3. Try dd - note it is /dev/diskx not /dev/diskxs3 (partition 3 or other on disk x). Another tutorial also has you convert the image; I haven't used that method but it seems to work for people:

dd if=/path/to/image of=/dev/diskx bs=512k && sync

I like to know what dd's progress is, so I use pv, which you can get using Homebrew or Macports:

dd if=/path/to/image | pv | dd of=/dev/diskx bs=512k && sync

You'll probably have to put sudo before each dd command.

I hope that helps - you'll definitely get something to work eventually, whether it's the image, method, or USB stick.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .