Trying to make bootable USB on OS X -- the disk you inserted was not readable by this computer ??


You've already got two working USB keys. You probably don't need to make another. Unless you're having an Ubuntu themed party, I suppose.

That's not an error related to the creation of the USB Boot Drive. That's an error you get after the dd operation completes successfully. OS X can't read the contents of a properly created Ubuntu boot drive. You now need to reboot and let reFind or the Mac's EFI loader find the drive.

If you're planning to install this copy of Ubuntu on your Mac, make sure you read, fully understand and then follow the guide for your specific year and model. If you don't, you'll have nothing but headaches.


Related videos on Youtube

Author by


Updated on September 18, 2022


  • Elemenop
    Elemenop 3 months

    So I formatted the USB thing to FAT, I tried using a 4GB and then figured maybe it's the disk so then I used a 2GB and got the same errors. Followed the instructions just as they are on the page...

    I do the install command and I can see the lights start to go on my USB drive like it's being used... it continues for a few minutes and then I get this error pop up that says the "disk you inserted was not readable by this computer"

    what's wrong here? I'm following all of these instructions properly and I've tried it several times each way. using osx 10.9.4 and trying to get a bootable USB so I can install ubuntu on another partition. I don't have a CD drive so I can't do that.

    By the way, It says under step 3 in a Note: that OSX adds the .dmg to the file so it comes out like blabla.img.dmg after the conversion. Am I supposed to edit the name of the file and remove that .dmg at the end or keep it? It doesn't say what to do about it in the instructions.

    • Admin
      Admin over 8 years
      amanthethy thanks!! Its funny how I didn't even think of testing out the USB stick because the error just threw me off! It works! Thank you for your help.