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For a while I went without using OS X, as I just preferred Ubuntu, and needed the extra space the partition I had for os x was taking up.

I have my Lion OS X on a portable HDD, but whenever I hit alt on boot neither my external disc drive or USB devices show up.

Any ideas on how to fix this issue?

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2 Answers 2

up vote 1 down vote accepted

If it does not show up in the EFI menu, then you should be able to hardwire some options into your Grub Loader (the default on newer Ubuntu installs). That'll boot past EFI and then load from Linux's bootloader.

With the devices installed, you may be able to just run "sudo update-grub" and it may be enough to probe for it. You will see output like this telling you what is found:

enter image description here

Otherwise, you could customize your /etc/grub.d/40_custom file to add it manually.

For OSX it would look something like this:

Snippet: How to Create a Mac Boot Entry in Grub2

menuentry "MacOS X Snow Leopard" {
insmod hfsplus
set root=(hd0,X) #change X to the Mac SL partition
multiboot /boot
}

And be sure to run:

sudo update-grub

Note: I don't have an apple to test this on for you, and it may be grub-efi rather than grub-pc for you. If that is the case, it should be pretty similar. That should get you most of the way there.

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Thanks, I'll try it when I get home shortly and get back to you on it! –  samayres1992 Nov 13 '12 at 16:28
    
Great, if you run into issues I will try to help you along. Unfortunately, I don't have the same hardware to try. –  nerdwaller Nov 13 '12 at 19:34

When you say "alt" are you using the below Ctrl+Shift+Option+Delete ?

Press the key combination "Control + Shift + Option + Delete" and hold it down while the computer starts up. This key combination will force the computer to ignore the normal startup disk, which is usually an internal hard drive. The computer will instead boot from any attached bootable devices, such as an external drive or CD.

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