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Trying to add nomodeset to the boot options of the 16.04 desktop installer.

Tried hdparm to make the USB writable, but it has no effect.

Tried isomaster to create a modified the iso before flashing it with Startup Disk Creator - USB isn't detected as bootable.

Looked at the https://help.ubuntu.com/community/LiveCDCustomization - it's an overkill that doesn't look promising. Edit: tried that, and it's not bootable.

Similar to this question that was shut down:

How to create a bootable usb stick that is not read only

Velkan
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  • UEFI or BIOS? Normally you just add nomodeset with f6 if BIOS or edit of grub as booting with e when booting live installer. But you can edit if desired. If UEFI just add nomodeset to /boot/grub/grub.cfg. If BIOS you have to add to syslinux boot configuration in /isolinux/text.cfg. I actually have nomodeset in my grub.cfg used to loopmount the ISO directly. https://help.ubuntu.com/community/Grub2/ISOBoot – oldfred Jun 06 '17 at 13:47
  • As I mentioned, nothing is writable. – Velkan Jun 06 '17 at 14:00
  • This question has already been answered here: https://askubuntu.com/questions/38780/how-do-i-set-nomodeset-after-ive-already-installed-ubuntu The difference is that here it's a live USB, but some answers probably apply. – Quidam Apr 26 '20 at 14:25
  • Here: https://askubuntu.com/questions/9262/change-liveusb-default-boot-options – Quidam Apr 26 '20 at 14:27
  • Does this answer your question? Change "LiveUSB" default boot options – Quidam Apr 26 '20 at 14:28
  • @Quidam, I have no idea, it was an eternity ago. To test the answer I have to find an empty drive, a computer to plug it into, download and flash an image (the current 18.04 or what it now? 20.04? it may even behave differently). – Velkan Apr 26 '20 at 17:07
  • It doesn't matter, as the questions are here as a knowledge base. – Quidam Apr 26 '20 at 17:08
  • @Quidam, well apparently it matters because I can't test now. – Velkan Apr 26 '20 at 17:20
  • It doesn't matter, if you are not interested by the answer anymore, because it's too old, and you moved to other things, the question and the answers are always here for people in the same cases, that's the reason why they forbid us to ask several times the same kind of question here. – Quidam Apr 26 '20 at 17:21
  • @Quidam, you're probably new here. I suggest you to read some stackoverflow meta threads about the old questions and insisting on accepting answers. There bound to be some interesting discussions and thoughts about that. – Velkan Apr 26 '20 at 17:41
  • Who did insist to accept answers?? I don't understand your point. I don't use AskUbuntu much, because I have a different OS, but I'm not really new here. – Quidam Apr 26 '20 at 18:09

4 Answers4

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Depending on how you created the USB boot drive, it will be read-write or read-only.

Cloned drive

A cloned drive created with the 'Startup Disk Creator' in Ubuntu 16.04 LTS or newer versions, has a hybrid iso9660 file system, which works both in DVDs and USB pendrives (and memory cards), but it is read-only by design, so you cannot edit anything in it. Also 'Disks' alias gnome-disks, and 'mkusb' (when cloning and creating live-only drives) make USB drives with a hybrid iso9660 file system.

Extracted drive

An extracted drive, for example

  • a persistent live drive created with mkusb or
  • a live-only drive created with Rufus,

can be edited. You can add nomodeset and other boot options to the boot configuration file, so that they will persist (survive to be used in the future). Edit boot/grub/grub.cfg in partition #3, 'usbboot' for mkusb. You may need to boot from another drive in order to mount the FAT32 file system read-write for Rufus.

New tips to make your USB boot drive with Ubuntu 19.10+

  • You can edit your binary iso file and replace the cosmetic boot options quiet splash with the boot option 'persistent ' or 'nopersistent' (the strings contain 12 characters, so the replacement can be done without any offset in the following part(s) of the iso file. You can do it with sed

    sed 's/quiet splash/persistent  /' standard.iso > persistent.iso
sed 's/quiet splash/nopersistent/' standard.iso > nopersistent.iso

    and clone the modified iso file, or flash directly with

    sed 's/quiet splash/persistent  /' standard.iso > /dev/sdx
sed 's/quiet splash/nopersistent/' standard.iso > /dev/sdx

    where x is the device letter for the USB pendrive.

  • You can do it with a safety belt using mkusb-minp

  • It is more convenient and also safer to use mkusb-plug for the whole process including the sed commands, and there is a graphical user interface.

  • You can do it yourself with an extracting method and get whatever combinations of boot options, that you like, according to this link

sudodus
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    Yes, it looks like a hybrid iso9660, so there is no fast way. For the actual video problem I went for complete install and tweaking afterwards. – Velkan Jun 07 '17 at 06:27
  • @Velkan, I'm glad that I could help to identify the problem, and that you found a solution for the installed system. Thanks for sharing your solution :-) – sudodus Jun 07 '17 at 07:24
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If you flash your image using rufus on windows using GPT boot structures then you can use (on Ubuntu 16.04 LTS): sudo mount -o remount,rw /media/cdrom /media/cdrom to remount your drive. I wouldn't recommend it but it does work.

Jensen Taylor
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You could try UNetBootIn. It's a software which allows you towrite to existing partitions on the usb stick, like fat32 or ext4. Persistence only works with fat32. However the usb stick is writeable due to its filesystem.

Unetbootin can be downloaded using 

sudo apt update && sudo apt install unetbootin
spark
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  • I'm not sure Unetbootin let you write to the partition, it rather put ISO on partitions. I'm not sure that it's useful anyway here to write to the partition, as the user ask for boot parameters.. It has no link with the persistance, it's a boot parameter. It has no link with the stick being read only neither. – Quidam Apr 26 '20 at 14:30
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hdparm is not the answer (see man hdparm).

Your USB stick is probably mounted read-only, but you don't give us that information.

Assuming your USB stick is on device /dev/sdx (it won't be, but I'm using /dev/sdx in the example, replace it with YOUR value)), you can mount it read/write via: 

sudo mount -o remount,rw /dev/sdx
waltinator
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