How to create a custom live only Ubuntu ISO to be used on a USB stick and with support for data persistence? about cubic HOT 9 CLOSED

• The ISO image will be written to and run only from a USB stick, and any changes done while using the live image should persist across reboots (I am still not sure whether to use a persistent overlay or a separate area).

Edit boot parameters

1. In Cubic, navigate to the Options page.
2. Click on the Boot tab in the header bar.

UEFI boot

3. Click in the file boot/grub/grub.cfg † in the left pane.
4. In the right pane, in the "Try Xubuntu without installing" section, add persistent just before quiet splash. (You may want to make similar changes to the other boot entries).
5. Optionally, remove file=/cdrom/preseed/xubuntu.seed since you are not using Ubiquity. (You may want to make similar changes to the other boot entries).
6. You might also want to change the name of the menu entry from "Try Xubuntu without installing" to something like "Xubuntu (Persistent)". (You may want to make similar changes to the other boot entries).

Legacy BIOS boot

7. Click in the file isolinux/txt.cfg † in the left pane.
8. In the right pane, in the ^Try Xubuntu without installing section, add persistent just before quiet splash. (You may want to make similar changes to the other boot entries).
9. Optionally, remove file=/cdrom/preseed/xubuntu.seed since you are not using Ubiquity. (You may want to make similar changes to the other boot entries).
10. You might also want to change the name of the menu entry from ^Try Xubuntu without installing to something like ^Xubuntu (Persistent). (You may want to make similar changes to the other boot entries).

† Note: boot/grub/grub.cfg is used for UEFI boot in Ubuntu 20.04. isolinux/txt.cfg is used for legacy BIOS boot in Ubuntu 20.04. I'm not sure what boot/grub/loopback.cfg is used for, so if you know or figure it out, please let me know.

Burn and use the ISO

11. Create a bootable USB using a program like Startup Disk Creator.
12. The first time you boot into the USB, the system will automatically create a new writable partition on the disk named writable. This will store your changes while you use the Live ISO.

Caution

Be very cautious about doing system updates/upgrades and making big changes to the Live USB. Eventually, the USB will become unusable (speaking from experience). It is best to install all of the updates and software you need in Cubic, and avoid doing too many updates or installing too many new packages to the persistent Live USB.

from cubic.

• The live OS must not show the Welcome screen (that is, the one with the "Try Xubuntu" and "Install Xubuntu" buttons).

  Simply remove Ubiquity, since you will not be using the customized OS to install Xubuntu.

   apt autoremove ubiquity ubiquity-frontend-gtk
  

• The live OS must not have the "xubuntu" user (i.e., the user created in a traditional Xubuntu Live OS) or, if not possible, that user must log into the system only with a password (no auto-login).

• The live OS will have at least two predefined users, say "powuser" and "stduser" (both protected by predefined passwords), but only one of them ("powuser") will have administration capabilities (that is, can use "sudo").

  Create the standard user.

  adduser stduser
  
  Adding user `stduser' ...
  Adding new group `stduser' (1000) ...
  Adding new user `stduser' (1000) with group `stduser' ...
  Creating home directory `/home/stduser' ...
  Copying files from `/etc/skel' ...
  New password:
  Retype new password:
  passwd: password updated successfully
  Changing the user information for stduser
  Enter the new value, or press ENTER for the default
          Full Name []: Standard User
          Room Number []:
          Work Phone []:
          Home Phone []:
          Other []:
  Is the information correct? [Y/n] Y
  

  Create the power user.

  adduser powuser
  
  Adding user `powuser' ...
  Adding new group `powuser' (1001) ...
  Adding new user `powuser' (1001) with group `powuser' ...
  Creating home directory `/home/powuser' ...
  Copying files from `/etc/skel' ...
  New password:
  Retype new password:
  passwd: password updated successfully
  Changing the user information for powuser
  Enter the new value, or press ENTER for the default
          Full Name []: Power User
          Room Number []:
          Work Phone []:
          Home Phone []:
          Other []:
  Is the information correct? [Y/n] Y
  

  Add the power user to the sudo group.

  usermod -a -G sudo powuser
  

• The live OS will have preinstalled extra packages (for instance, gcc and make).

  Install the apt-add-repository command.

  apt update
  apt install software-properties-common
  

  Add the repositories or PPAs for your packages, as needed.

  apt-add-repository universe
  

  Install the packages you want.

  apt install gcc make
  

• The live OS will have preconfigured settings (including locale "en_US" and optionally "it_IT", keyboard layout "it" and timezone "Europe/Rome").

  Install English language packs.

  apt install language-pack-en language-pack-en-base
  

  Install Italian language packs.

  apt install language-pack-it language-pack-it-base
  

  Select your locale(s).

  dpkg-reconfigure locales
  

  In the text based dialog, use the following to navigate.

  • Use Tab and Shift+Tab to navigate to different sections.
  • Use Space bar to select items.
  • Use the ↑ and ↓ keys to scroll through the list.
  • Use Enter to select the <Ok> or <Cancel>options, after they have been highlighted.

  Press Space bar to select en_GB.UTF-8 UTF-8 for English / Great Britain.

  [ ] en_GB ISO-8859-1
  [ ] en_GB.ISO-8859-15 ISO-8859-15
  [*] en_GB.UTF-8 UTF-8
  

  Also, press Space bar to select it_IT.UTF-8 UTF-8 for Italian / Italy.

  [ ] it_IT ISO-8859-1
  [*] it_IT.UTF-8 UTF-8
  [ ] it_IT@euro ISO-8859-15
  

  Use Tab to highlight <Ok>, and then press Enter.

  On the next page, scroll through the list and highlight it_IT.UTF-8.
  Use Tab to highlight <Ok>, and then press Enter.

  The locales will be generated.

  .
  .
  en_GB.UTF-8... done
  .
  .
  it_IT.UTF-8... done
  .
  .
  

  The LANG variable will be set to it_IT.UTF-8.

  cat /etc/default/locale
  

  Set the time zone.

  ls -l /etc/localtime
  ln -frs /usr/share/zoneinfo/Europe/Rome /etc/localtime
  ls -l /etc/localtime
  

Finally, generate your custom ISO and test.

from cubic.

Many many thanks! It worked like a charm.

After the locale (re)configuration, I also ran:

dpkg-reconfigure keyboard-configuration

to change the default keyboard layout from English to Italian.

Specifically:

1. In the first screen, I selected Generic 105-key PC (intl.) as the model of the keyboard
2. In the second screen, I selected Italian as the layout
3. In the third screen, I selected Italian again as the specific layout
4. In the fourth screen, I select The default for the keyboard layout as the key to function as AltGr
5. In the fifth screen, I selected No compose key as the compose key
6. Finally, in the sixth screen, I selected No as the answer to the question Use Control+Alt+Backspace to terminate the X server?

Thank you.

from cubic.

Thank you so much! 🥇 👍

Concerning the GRUB's /boot/grub/loopback.cfg file, it is used by GRUB2 to boot from an ISO image file stored on some storage medium accessible at boot time. However, I never used it.
Here are some interesting references:

• https://www.gnu.org/software/grub/manual/grub/html_node/Loopback-booting.html
• https://help.ubuntu.com/community/Grub2/ISOBoot/Examples
• https://wiki.archlinux.org/title/Multiboot_USB_drive#Workstation_live_medium

from cubic.

sguazt,

Since you don't want the Welcome screen (with the "Try Xubuntu" and "Install Xubuntu" buttons), do you still want the installer available, in order to allow a user to install the OS, or do you intend to never use this ISO to install the OS?

from cubic.

Hi,
I will never use the ISO to install the OS.

from cubic.

I still owe you a solution to your last question:

• The ISO image will be written to and run only from a USB stick, and any changes done while using the live image should persist across reboots (I am still not sure whether to use a persistent overlay or a separate area).

In the mean time, see if the above steps work for you.

from cubic.

Alternative approach to remove "Try Xubuntu" / "Install Xubuntu" welcome dialog

In the previous comment, I suggested removing the Ubiquity package in order to get rid of the "Try Xubuntu" / "Install Xubuntu" welcome dialog.

Alternatively, if you do not want to remove Ubiquity, you can disable the Ubiquity service.

On Cubic's Terminal page, execute the following:

rm /etc/systemd/system/graphical.target.wants/ubiquity.service

This will log you directly into the Live environment. The "Install Xubuntu" icon will remain on the desktop and the application menu. You will still be able to install Xubuntu from this Live environment by clicking on one of these icons.

from cubic.

I am closing this issue with the comments above.

If the approach I suggested for creating a persistent Live USB does not work, feel free to reopen this issue.

from cubic.