Ubuntu on USB in Mac OS X

Did you MD5 test the ISO you downloaded?
Have you tried the USB device in another system to see if it is ok and it's not your Mac being rubbish?

The USB works fine, on my Mac and on other machines.

When I install Ubuntu on it using windows it works fine on PC, but when I install Ubuntu on it in a Mac it doesn't boot up, even though I can see the Ubuntu it installed in it correctly.

I install Ubuntu in the USB using a Live CD which I burn from the ISO image file.

Then your issue is the mac. Not ubuntu. What model is your mac?

I have Mac OS X 10.6 Snow leopard. And my laptop is MacBook Pro 13"

If there is more than 1 USB port, try another port, reboot and hold option

I tried that, it still doesn't work, I even tried it on another MacBook Pro 13"

if you tried it on 2 different macbook pros 13" and it doesn't work, then it's a problem with the mac book pro 13"s.

also, you might want to try a different version of ubuntu. version 10.10 won't install on my and other people's toshiba netbook while 10.04 works. which version are you trying to install?

if you tried it on 2 different macbook pros 13" and it doesn't work, then it's a problem with the mac book pro 13"s.

also, you might want to try a different version of ubuntu. version 10.10 won't install on my and other people's toshiba netbook while 10.04 works. which version are you trying to install?

Yes I tried Ubuntu 10.10 I have had this problem for months now. I know it is the problem with the MacBook Pro 13" there is something about the BIOS that is not compatible.

The Ubuntu OS works fine if you install it in the HDD for a MacBook Pro 13", but does not work if you install it on a USB. I am sure other people are having the same problem, as I am sure I am not the only person in the world trying to work with a USB Live Ubuntu in a MacBook Pro 13".

http://en.wikipedia.org/wiki/Live_USB

look under limitations, second point. talks exactly about what I am facing. There is something in the BIOS I need to change in Ubuntu to allow the USB to be recognised by the MacBook Pro 13"

It seems like we are on the same boat though I would like to boot via Firewire instead of USB.

The simply explanation to this that I have came across was that Apple does not use BIOS though it is there, instead it uses EFI and because of this, a foreign OS on an Apple system can only boot from an optical drive or an internal drive.

Alternatively you can place the Ubuntu /boot directory on an internal partition or on a CD and the rest of Ubuntu on an external. This way it would be possible to boot Ubuntu on a Mac Intel via external drive. I am on the verge of getting this together and I have read many who have succeeded.

Also another option would be to have OS X on an external drive since and run Ubuntu internally. You don't have to worry about updating the any /boot directory when you choose to upgrade Ubuntu with this method.

http://diigo.com/0gmqf
http://diigo.com/0gmqg