One of the major advantage of Linux is you can customize it however you like. You can add a new feature, remove an existing feature, modify the appearance of the Linux distribution and many. You can either customize an already installed Linux distribution or create a new customized image from a Linux ISO. In this guide, we are going to learn what is Cubic and how to create a custom Ubuntu live ISO image with Cubic application.
Table of Contents
What is Cubic?
Cubic, stands for Custom Ubuntu ISO Creator, is a free, open source graphical application to create a customized bootable Ubuntu Live CD (ISO) image.
Cubic allows you to easily and effortlessly create a customized Ubuntu live cd. It has an integrated command-line chroot environment where you can do all customization as listed below:
- Install new packages,
- Remove existing packages,
- Install additional Kernels,
- Add more background wallpapers,
- Add files and folders.,
- Modify existing ISO
- And more.
Cubic's Graphical interface allows effortless navigation (back and forth with a mouse click) during the live image creation process.
Since Cubic is used to make Ubuntu live images, I guess it can also be used in other Ubuntu flavours and derivatives such as Linux Mint. I tested it in Ubuntu 20.04 LTS, 18.04 LTS and 16.04 LTS versions. It worked just fine!
Install Cubic in Ubuntu
To install Cubic on Ubuntu 18.04 and newer versions, run the following commands one by one in your Terminal:
$ sudo apt-add-repository ppa:cubic-wizard/release
$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys B7579F80E494ED3406A59DF9081525E2B4F1283B
$ sudo apt update
$ sudo apt install cubic
"Cubic Classic" works on older Ubuntu LTS versions such Ubuntu 14.04.6 LTS Trusty Tahr and Ubuntu 16.04.6 LTS Xenial Xerus. To install Cubic Classic on your Ubuntu system, run:
$ sudo apt-add-repository ppa:cubic-wizard/classic
$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys B7579F80E494ED3406A59DF9081525E2B4F1283B
$ sudo apt-get update
$ sudo apt-get install cubic
Please note that you should not install both "Cubic" and "Cubic Classic" version at the same time. They conflict with one another and may not work. Also projects you created with Cubic can't be opened with Cubic Classic version.
Create Custom Ubuntu Live Cd Image With Cubic
Launch Cubic from Dash or Application launcher. The following screenshot shows the default interface of Cubic application.
Select a project directory to store the customized Ubuntu live ISO image and click Next. For the purpose of this guide, I will be using /home/sk/cubic/ as my project's directory.
Select the Ubuntu ISO image you want to customize. Here, I chose Ubuntu 20.04 LTS desktop image. Once the ISO image is selected, Cubic will automatically fill the details of original and custom images. You can modify the custom ISO image's details as you please.
Cubic will now start to locate the compressed Linux filesystem, extract the compressed filesystem and copy the important files from the original ISO image. It will a couple minutes. Please be patient.
Now you will be placed inside the Cubic command line virtual environment.
From here, you can start customizing the Ubuntu ISO as per your liking. You can update the packages, install your favorite applications, remove unwanted applications from the ISO, install additional Kernels, add files and folders and add wallpapers, install themes, modify the software repositories and so on.
Please note that you don't need to use "sudo" to add or remove something from the ISO, because we've already logged in as root user.
I am going to install Vim application in the live cd, so I ran the following command in the virtual environment:
apt install vim
Similarly, add additional software or remove unwanted software from ISO. If you modified the sources list, don't forget to update the software repository list using this command:
apt update
You can also add files or folders to the live cd. Copy the files/folders (right click on them and choose copy or CTRL+C) and right click in the Terminal (inside the Cubic window), choose Paste file.
Click Copy at the top corner of the Cubic wizard to paste the files/folders in the live ISO image.
You can add your own wallpapers if you want. To do so, cd into the /usr/share/backgrounds/ directory,
cd /usr/share/backgrounds
and drag/drop the images into the Cubic window. Or copy the images and right click on Cubic Terminal window and choose Paste file(s) option. Also, make sure you have added the new wallpapers in an XML file under /usr/share/gnome-background-properties, so you can choose the newly added image Change Desktop Background dialog when you right-click on your desktop.
Once you are done with the customization, click Next to continue.
Cubic will start analyzing the customizations and preparing other important options such as identifying boot kernels, boot configuration, pressed files, installed packages, and creating the package manifest for typical and minimal install, and Saving the package manifest etc.
Select the packages that will be removed after a typical or minimal install. Go through the list and choose the software that you want to remove from the custom ISO and click Next to continue:
This is important section. In this wizard, you need to configure the ISO kernel, Preseed and ISO boot settings for the customized ISO. Select the Kernel that will be used to boot the customized Ubuntu live ISO in ISO Kernel tab. Then, update, add or delete preseed used to automate the installation under the Preseed tab. Finally, From the ISO boot tab, you can configure or customize the boot menu entries. After configuring the Kernel related parameters, click Next.
Select the compression algorithm for the Linux filesystem. By default, Cubic will use gzip compression. The other available compression methods are lz4, lzo, zstd, lzma, and xz. The compression algorithms are shown in a graph format as shown in the following screenshot. The upper side of the graph indicates lower compression and bottom side of graph indicates the higher compression.
If you choose a lower compression algorithm from upper side of the graph, for example lzo, lz4, the image creation process will be faster but the resulting image will be larger in size. If you choose higher compression algorithms such as zstd, lzma, xz from the bottom, the image creation will be slower but you will get the smaller size image.
After choosing the preferred compression, click Generate button to create custom Ubuntu live cd image with Cubic:
Now the custom live ISO image creation process will start. It will take a couple minute depending upon your system's speed. Once the image creation is completed, click Finish button.
Finally, Cubic will list the details of newly created customized ISO image. Click Close button to exit Cubic. If you want to delete all project files except the ISO and checksum files, check the box that says "Delete all project files..." at the bottom and then click Close.
The customized image will be saved in your Cubic project directory.
Create a bootable USB with this ISO image and test it on your system to verify if it works. There are many tools available to create bootable USB drive in Linux. Here are some for your reference:
- How To Create Multiboot USB Drives With Ventoy In Linux
- Create Persistent Bootable USB Using Ventoy In Linux
- Create Bootable USB Drive With USBImager In Linux
- Etcher – A Beautiful App To Create Bootable USB Drives And SD Cards
- Popsicle – Create Multiple Bootable USB Drives At Once
- How To Create Persistent Live USB On Ubuntu
- Bootiso Lets You Safely Create Bootable USB Drive
- MultiCD – Create Multiboot CD, DVD, and USB Images
- How To Create Bootable USB Drive Using dd Command
Modify Custom Ubuntu Live Cd Image Using Cubic
You might want to do some changes in the existing custom ISO. To do so, open the Cubic application and choose the directory and then select the path of custom ISO (not the original) that you want to modify. And the rest of the steps are exactly same as above.
Resource:
