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I've just downloaded ubuntu 12.04 and wanted to make a fresh install on my macbook pro, I followed the instructions given here and when the operations are completed I get this result:

The disk you inserted was not readable by this computer

Obviously, when I restart the pc, it cannot find any bootable device.

Note I've tried using Lion OSX

Thank you very much for your help!

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marked as duplicate by Chan-Ho Suh, Uri Herrera, Eric Carvalho, Kevin Bowen, bcbc May 29 '13 at 4:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Similar question? – fossfreedom May 3 '12 at 11:37
up vote 1 down vote accepted

I've done a little bit of searching and it seems to have something to do with the new hybrid iso image type being used that OSX doesn't seem to understand?? I haven't found anything that could convert the iso to something it can understand yet. If anyone finds the answer I'd love to know how to successfully do this in OSX.

Update: I think I found out how to get around this. So in the instructions in the link above there is needs to be a change. Instead of converting the image using hdiutil, simply drop the iso in the Disk Utility app on the left side and try and mount it. It will fail but it will give you the location of that partition. From there, you can use the dd command to dump this partition into a new iso image where 'diskNsN' is the partition.

dd if=/dev/diskNsN of=./ubuntu.iso bs=1m

I was able to mount this image as well as take it and dump it on my USB thumb drive as the instructions originally instructed. I just popped my thumb disk back in and my OSX 10.7.3 sees it just fine. I haven't tried booting it but it looks ok. So it looks like the new hybrid iso images being distributed have the image inside the image which I don't quite understand but by pulling it out mac seems fine with it.

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No, it doesn't have to do with the iso. Simply put, Macs do not like you to boot another OS off USB. They've been designed to stop that. The Ubuntu help page is misleading in that regard, because it only says they "suggest" you use a CD install. Really, what it should say is that only the CD install is guaranteed, and doing it the USB way has been found to be hit-or-miss (and usually requires more work, more tricks). – Chan-Ho Suh Apr 26 '12 at 19:35
Try to boot it to see if it works. Mounting it is not usually the issue. Booting is. – Chan-Ho Suh Apr 26 '12 at 20:16
Mounting it was an issue with the hybrid iso image. Your right, it doesn't boot though. The same original iso I could generate a virtual machine from it, then mount the same iso and create the USB start disk within Ubuntu 12.10 just fine. They look the same but it must be missing something after I stripped it out of the original iso. – Minwedar Apr 26 '12 at 20:33
I'm not sure if there is actually two questions here. 1) can you ever boot and ubuntu image on a mac hardware and 2) can your create the usb boot thumb drive on OSX (assuming 10.7 "Lion"). I've always assumed the first one isn't possible but I use to make all my images within OSX before and the last couple of releases of Ubuntu this hasn't been possible due to the iso current iso format. – Minwedar Apr 26 '12 at 20:35
The hybrid iso problem is why they have a special mac iso; it's available as an alternate download. But it's still problematic booting that off a USB. The OP has an optical drive. I'd advise him/her or anybody in a similar issue to use it. – Chan-Ho Suh Apr 26 '12 at 20:36

I had the same problem. In the end I managed to create a bootable stick using a different approach described here.

Basically you use a normal FAT formatted USB stick and put the ISO image there. Then create a "efi" folder with some necessary files, including a grub.cfg (attachment in the above forum post). Once you've installed rEFIt you should be able to boot from the stick.

Just make sure you have the correct file paths in the linux and initrd commands in grub.cfg.

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