There are hundreds of Linux Live CDs available online, and almost all are absolutely free. Many are indispensable for various purposes, such as desktop recovery, security, penetration testing, system rescue, drive cloning, and much more. Then, there are hundreds of Linux distributions that work as a bootable CD.

Of course, you don't want to carry around heaps of CDs. Thankfully, you can combine multiple ISO files into a single bootable ISO image using MultiCD. It saves space, lets you carry a huge range of tools, and is completely free.

What Is MultiCD?

MultiCD is a Linux shell script you can use to build a multiboot CD image. It works with a wide range of bootable Live CDs, including Arch Linux, Debian, Mint, and Ubuntu (full list). There are many options - your only limit is the size of the disk you use.

You can also use MultiCD to create a bootable USB flash drive, although it will be a read-only drive. As most people no longer use spinning CDs for storage, instead opting for super cheap flash memory, it is highly likely you have a spare USB flash drive lying around. You can find details on using MultiCD with a USB flash drive toward the end of the article, plus a few alternative options.

Create a Multiboot CD With MultiCD

Now, here's how you combine multiple ISO images into one.

1. Download and Extract MultiCD

For reference, I'm running this tutorial on Ubuntu Desktop 20.04.

The first thing to do is to download and update MultiCD. Press CTRL + ALT + T to open the terminal. Alternatively, right-click your desktop and select Run a Terminal. Now, input the following command to download MultiCD from its git repository:

        git clone git://github.com/IsaacSchemm/MultiCD.git
    

Alternatively, you can download the latest MultiCD version via the project's GitHub link.

Next, create a new folder. I've named mine MultiCD to keep things easy. Now, extract the contents of the MultiCD archive to the MultiCD folder.

2. Copy Your ISOs to the MultiCD Folder

Now, you must select the ISOs you want to include in your multiboot CD. You'll have to download the individual ISO files before continuing, making sure to use files on MultiCD's supported ISOs page.

Furthermore, you must rename each ISO before copying it to the MultiCD folder. The MultiCD script expects file names in a certain format. If you don't use that format, it won't work. The specific file names are also available on the supported ISOs page. For example, you would rename your Linux Mint ISO to linuxmint.iso.

Here's how my MultiCD folder looks before running the script in the next section.

multicd renamed isos

If you want to try MultiCD but don't want to spend ages downloading ISOs, check out this list of the smallest free Linux distros. They're tiny - but functional!

3. Run the MultiCD Creator Script

Once you have your ISOs in order and your disc in the drive, you're ready to create your multiboot CD.

Open a terminal in the MultiCD folder containing your ISOs. Now, input the following command:

        Chmod +x multicd*.sh

./multicd.sh

You may have to run the script as root for it to work. If that is the case, add sudo to each command and enter your password when challenged.

After the script completes, a new folder named build will appear in the MultiCD folder. You'll find the multiboot output ISO in the new folder.

4. Burn the MultiCD to Disc

Your final step is to burn the MultiCD ISO to a disc. Now, I no longer own a disc drive. However, the following steps work for both discs and USB flash drives, so anyone can follow along.

select destination disk for multicd
  1. In the MultiCD build folder, right-click the ISO file, and select Open With Disk Image Writer.
  2. Select the Destination, be that a USB drive or a CD/DVD. Now, select Start Restoring.
  3. Wait for the process to complete. When it finishes, your multiboot CD or USB flash drive will be ready to go.

Now you have a bootable Linux CD, you can check out the risks of dual-booting Windows and Linux on the same system.

Create a Multiboot USB with Multisystem

MultiCD is a great way to create a multiboot CD or DVD, combining multiple ISOs into a single file. MultiCD also works with bootable USB flash drives, too - but it isn't the only option available.

The next part of this article guides you through the creation of a multiboot USB drive using the Multiboot LiveUSB Tool.

1. Download and Configure MultiSystem

First up, head to Pendrivelinux and download the MultiSystem LiveUSB Tool. Now:

  1. When given the choice, Open with Archive Manager.
  2. Select Extract in the top-left corner, and extract the file to a memorable location.
  3. In the folder you extracted to, right-click and select Open in Terminal.
  4. Now, input the following command:
            ./install-depot-multisystem.sh
        

If the install fails and returns the Error: xterm, run sudo apt install xterm, let the process complete, then attempt to install MultiSystem again.

2. Add Linux ISOs to MultiSytem

Now, head to Accessories and select MultiSystem. Next, select your USB drive from the bottom panel, then select Confirm. If the process fails, restart your system.

multisystem select disk

You can now begin to add Linux ISOs to MultiSystem in preparation for the creation of the multiboot USB drive. However, the ISOs must be added one at a time, as well as entering your password.

Unfortunately, this makes the construction of a large multiboot USB drive somewhat time-consuming using MultiSystem.

multisystem with isos

Drag and drop the Linux ISOs you want to add to your MultiSystem USB drive. MultiSystem will automatically detect the ISO, assign it a name, and add it to the GRUB bootloader list.

Unsure which ISOs to include? Consider our list of the best Linux distros to dual-boot.

3. MultiSystem Advanced Menu

MultiSystem has an advanced menu, too. The advanced menu contains the option to download other Linux Live environments for use with MultiSystem. There is a lengthy list to choose from, covering various Linux tools and operating systems.

Once the download completes, you drag the ISO into MultiSystem, ready for use.

multisystem download extra isos

The advanced menu also contains the options to test your multiboot USB drive using QEMU or VirtualBox. Also, you can customize GRUB Settings, as well as the addition of command line boot options.

Easy Ways to Merge ISO Files

These two methods allow you to combine multiple ISO files into a single file. It saves physical space (no more piles of discs) and means you can carry around an extensive selection of tools and operating systems.