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I downloaded Ubuntu .iso file from and wanted to make a bootable USB stick from my MacBook Pro, I use OS X 10.8 (Mountain Lion).

I followed instructions from here.

When I did do the sudo dd if=/path/to/downloaded.img of=/dev/rdiskN bs=1m command, in 88 seconds it said:

The disk you inserted was not readable by this computer.

where I see "Initialize...", "Ignore" and "Eject" buttons

and the Terminal gave me following message:

694+1 records in
694+1 records out
728018944 bytes transferred in 88.467946 secs (8229183 bytes/sec)

My question is NOT how do I install Ubuntu after this, my question is how do I "recover" my USB stick? If I get it out and insert back it gives me the same error message that my disk is not readable.

When I try to use sudo gpt recover I get the same message about my disk not being readable, and this in Terminal:

gpt recover: /dev/disk2: error: device contains a MBR
share|improve this question
My guess would be that clicking Initialize should re-format the disk. It will erase all data copied there from the .img file, but it will make it visible in MacOS again (and empty). You can't really physically break a USB drive by copying data to it. – Sergey Sep 28 '12 at 0:53
up vote 2 down vote accepted

Apple seem to be doing everything they can to stop people from installing from usb for some odd reason.

I completely killed my old macbook pro trying to put lubuntu on it and had to install osx on it in the end. I will try again one day..

My guess is that you should format the USB to the appropriate format using the disk utility.

share|improve this answer
Thanks, Magpie! It works now – Artem Naumov Sep 28 '12 at 0:53
Pleased it helped. – Magpie Sep 30 '12 at 14:12

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