
Usually, creating a Bootable USB for installing an operating system consists of three basic steps: Formatting the USB device, downloading software to create the bootable USB, and writing the installation file. Regardless of whether you use Windows or Linux to create the device, there are various tools (for example, rufus) that will help you make this process simple and fast. However, when you want to use your USB to install a new operating system, you will have to repeat the above steps, resulting in losing the old operating system. Fortunately, there is a solution to the problem, which is called multiboot USB.
Multiboot USB is the ability to have multiple operating systems on a single bootable USB device. There are various applications, such as WinSetupFromUSB, YUMI, and MultiSystem, that can create a multibootUSB. However, in this article we will work with Ventoy, which is the largest cross-platform application.
What exactly is Ventoy?

Ventoy is a new open source application that allows you to create multiple bootable USBs at once. While most applications require you to format the device every time you change the system, Ventoy can write the installation file of the new operating system without having to remove the old one.
Installing and managing the application is simple. All you need to do to create a multiboot USB is install Ventoy on your USB device, and then copy the ISO files of the systems you want to use to the device.
What's left to do now is boot from the device you installed Ventoy on. After selecting the device from the boot menu, the application will display a menu with the available operating systems.
Below is a list of Ventoy's features:
- 100% Open source.
- It does not decompress ISO files to USB.
- Legacy and UEFI support.
- Persistence support.
- Support for files larger than 4GB.
- Customized boot menu.
How to create a multiboot USB:
Below, you can see the process of creating a multiboot USB. Please note that we are using Ubuntu 20.04 for the following examples.
1) Download the Ventoy app
Download the application installation file.
2) Unzip the files

Unzip the file you just downloaded. You can unzip the file using the command:
tar -xvf ventoy-1.0.12-linux.tar.gz
3) USB device

Connect your device, and type the command lsblk. This will show you the name of the USB in the system.
4) installing Ventoy on the USB device

Once you have connected your device, you can proceed with installing the application. You can install the application by typing the command:
sudo sh Ventoy2Disk.sh -i /dev/X
Note: You should replace X with the name of your device. For example: sdb.
5) Check the mount status

Before we proceed to create a multiboot USB, you need to make sure that your device still has a mount point. If there is no mount point, you will need to remount the device.
6) Copying the ISO files

Copy the system installation files onto the USB device.
7) Reboot and system selection

After the files are copied, restart your computer, and choose to boot from your device.
If you have done all the steps correctly, you should see the application menu. From this menu, you can choose which operating system you want to install or run in live format.
Source: fossbytes.com
