Linux – How to create a bootable USB from a bootable ISO with the command line on Linux

bootable-mediaddiso-imageisolinuxlinux

I have a CD that's created from an ISO file which I use to install a custom version of Ubuntu via plop linux.

The cd works fine but I'd like to use a bootable USB drive instead.
I used the command dd to try and create the bootable USB:

dd if=filename.iso of=/dev/sdb1 bs=4k

Now this does copy the files and make the USB bootable but I get the error "Missing operating system"

Any ideas?

Best Answer

Ok after some research I've figured out a solution, and I'll go through it step by step. Problem was two-fold.

  1. Plug in the USB flash drive and determine the device it's mounted on with the command:

    sudo fdisk -l

    This time around it was /dev/sdc1 for me, so I'll use that as my example.

  2. Umount the device

    umount /dev/sdc1

  3. Not sure if necessary but I formatted the drive in FAT32, just in case

    sudo mkdosfs -n 'USB-Drive-Name' -I /dev/sdc -F 32

  4. Now my ISO was using isolinux not syslinux. I knew it worked with CDs so I figured out that I needed to call the isohybrid command, which allows for an ISO to be recognized by the BIOS from a hard drive.

     isohybrid filename.iso

    You can find out more about this command here, but this was the cause of the message "Missing Operating System" The first problem was fixed, but now it said "isolinux.bin was missing or corrupt"

  5. The next step is to copy the iso. My second problem lay here, where I was copying to the partition, sdc1, not the device, sdc.

    sudo dd if=filename.iso of=/dev/sdc bs=4k

    This seems to work just fine, but the forum where I got the last fix, it was recommended to do the following before unplugging the device:

    sync
sudo eject /dev/sdc
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