Trying to make an Ubuntu Server USB, and obviously it has to write the ISO to the disk, not just to a partition. I'm running dd if=ubuntuimage.iso of=/dev/sde and most of the time it completes. Sometimes it says it completed it at some ridiculous speed (like 300mb/s) and doesn't change a thing.

I open the disk in gnome-disk-utility and the disks shows multiple partitions - basically each attempt to dd the disk. Naturally, it can't be booted properly like this.

So I've tried using gparted,parted,fdisk, and even diskutil in Windows to clear the partition table. I've used the Kingston formatting tool as well. Windows reports that the partition table looks fine. Back into Ubuntu, run sudo partprobe and we're back to square 1. Then I write to it with dd or Rufus in Windows, and all of the partitions resurface, and the USB won't boot properly (typically installer loads and says it's missing files, as they were never copied correctly).

This has happened with multiple USB sticks, all after I dd them. Disk destroyer jokes aside, what else can I try besides throwing the USB out?

  • 3
    With dd you create a hybrid drive which does not have a typical partition table. And then ISO may have written random data into the location in MBR that has partition table info. Then gparted or other partition tools see total corruption and fail. Often best to just zero out MBR. sudo dd if=/dev/zero of=/dev/sdX bs=512 count=1 This deletes entire MBR, so make sure sdX is correct drive like sdf, sde etc or else DD is not a joke.
    – oldfred
    Jan 13, 2017 at 21:55
  • 1
    Possible duplicate of How do I make a bootable Ubuntu USB? Jan 13, 2017 at 21:58

1 Answer 1

  1. Please check with md5sum in linux or Md5summer in Windows, that the iso files was downloaded correctly.


  2. If the md5sum is bad, download again. The torrent method is more likely to succeed than a regular download.

  3. If the md5sum is good, use the dd method again, or do it safer with mkusb, and edit your question to post the output of the dd command line or mkusb,

  4. After that, run

    sudo lsblk -f
  5. If it looks good, but fails anyway, please reboot. If it still fails, please try to wipe the drive (overwrite with zeros). You can do it from mkusb's wipe menu.

  6. Reboot. There should be no partition table. If there are still some partitions and file systems, I think the drive is failing, 'grid-locked'.

See also this link (about an SD card, but it is the same kind of memory inside.)

Unable to format SD card

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