I can make a live CD image from the original 16.04 ISO image following these instructions:


My "remastered" ISO boots fine using kvm.

When I use the original 16.04 source ISO in "startup disk creator", I get a bootable USB, of course.

However, when I use my remastered ISO with "startup disk creator", it does not result in a bootable USB (at least with the PC I'm trying to boot it with). I notice that the USB I get from my remastered ISO shows up as only (say) /dev/sdb, but a USB from the original ISO (same USB stick) shows up as: /dev/sdb, /dev/sdb1, /dev/sdb2

So, I'm guessing maybe this has something to do with UEFI. But how can I make a USB stick created from my remastered image bootable?

  • 1
    i think you're on the right track: the guide you linked is old and doesn't say much about UEFI. makes me want to read the scripts the official live install cds are created with, if no other documentation is forthcoming. – quixotic Mar 29 '17 at 0:04
  • First, you might try something other than Startup Disk Creator. See this page of mine for some comments. Second, if the disk you're getting lacks partitions, then that suggests a pretty basic difference in the USB drives created by the two programs. I don't know offhand how a typical EFI would respond to a USB drive with a filesystem written to it directly vs. a partitioned disk. That might be the source of the problem -- or it could be that critical EFI boot files are missing from something. – Rod Smith Mar 29 '17 at 13:22
  • @RodSmith thanks, I'll take a look at your page. I'm not sure what "two programs" you're referring to? – Croad Langshan Mar 30 '17 at 18:40
  • @quixotic any idea where those scripts are? I'm failing to find them (I'm assuming they exist!)... – Croad Langshan Mar 30 '17 at 20:13
  • this blog post refers to ubuntu-defaults-builder and its dependency livecd-rootfs (seems built on the debian live-build tool). the post's reference links are informative. (all of those are packages you can install on recent ubuntu releases.) – quixotic Mar 31 '17 at 3:26

Run isohybrid(1), which will rewrite the ISO to make it USB bootable:

$ isohybrid customized_ubuntu.iso

Then you can use Startup disk creator, or some other tool, to write the image to a USB disk.

Startup disk creator (which lives in package usb-creator) simply ends up doing the equivalent of a dd, at least for ISO images (I didn't check what it does for .img files), and so is unrelated to this problem.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.