I followed the instructions here and I got a dmg instead. This is what I entered:

cd Desktop
hdiutil convert ubuntu-12.10-desktop-amd64.iso -format UDRW -o ubuntu-12.10-desktop-amd64.img

Then it gave me a dmg. What should I do?


From that very same documentation:

Note: OS X tends to put the .dmg ending on the output file automatically.

It seems it's not a problem. Just continue to the next steps, and when prompted for the file name, be sure to provide the correct one, with the .dmg extension. That's all.

  • It still says 'no mountable file systems' when I click on the new file. Is this a problem? Should I just continue? – user123553 Jan 16 '13 at 0:10
  • I don't know, I'm not a Mac OS X user. The instructions don't say a thing about clicking on the file, so I'd continue without worrying. – Jorge Suárez de Lis Jan 16 '13 at 0:44

Try this command,

hdiutil convert -format Rdxx -o ubuntu-12.10-desktop-amd64.img ubuntu-12.10-desktop-amd64.iso

Use Rdxx instead of UDRW.


Find the DMG file in finder and rename it to remove the trailing "dmg" extension. (Finder will ask you if you're sure. You are.)

Once you've done that, everything else will work as expected.


An .iso file and an .img file can normally be used interchangeably with little or no effect. Just rename the file so that it includes a .img extension.

cp ubuntu-12.10-desktop-amd64.iso ubuntu-12.10-desktop-amd64.img

If you get stuck, you can burn an image to DVD, as well as a thumb-drive.

  • When I try to open it, it says 'no mountable file systems' I tried renaming it and it doesn't work. I tried entering the command you suggestion and it didn't do anything. I am just trying to make a usb out of it so I can try it out. If it is this frustrating just to download then I might just say f- it and stick with osx – user123553 Jan 15 '13 at 23:37
  • I'd try the DVD route before USB. See this to see why. – Chan-Ho Suh Jan 16 '13 at 0:07

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