2 Ways to Create an ISO from a Bootable USB in Linux

In this article, we will show you how to create an ISO from a bootable USB drive in Linux. We will explain two ways to achieve this: via the command line interface (CLI) and a graphical user interface (GUI) program.

Create An ISO From A Bootable USB Drive Using dd Tool

dd is a commonly used command-line tool for Linux and other Unix-like operating systems, used to convert and copy files.

To create an ISO image from a Bootable USB Drive files, first you need to insert your USB drive and then find the device name of your USB using following df command.

$ df -hT
Sample Output
Filesystem     Type      Size  Used Avail Use% Mounted on
udev           devtmpfs  3.9G     0  3.9G   0% /dev
tmpfs          tmpfs     787M  1.5M  786M   1% /run
/dev/sda3      ext4      147G   28G  112G  20% /
tmpfs          tmpfs     3.9G  148M  3.7G   4% /dev/shm
tmpfs          tmpfs     5.0M  4.0K  5.0M   1% /run/lock
tmpfs          tmpfs     3.9G     0  3.9G   0% /sys/fs/cgroup
/dev/sda1      vfat      299M   11M  288M   4% /boot/efi
tmpfs          tmpfs     787M   56K  787M   1% /run/user/1000
/dev/sda5      ext4      379G  117G  242G  33% /media/tecmint/Data_Storage
/dev/sdb1 iso9660 1.8G 1.8G 0 100% /media/tecmint/Linux Mint 19 Xfce 64-bit

From the output above, you can clearly see that our attached USB device name is /dev/sdb1.

Now you can run the following command to create an ISO from a bootable USB drive as shown. Make sure to replace /dev/sdb1 with your USB drive and /home/tecmint/Documents/Linux_Mint_19_XFCE.iso with the full name of the new ISO image.

$ sudo dd if=/dev/sdb1 of=/home/tecmint/Documents/Linux_Mint_19_XFCE.iso

In the above command, the option:

  • if – means read from specified FILE instead of stdin.
  • of – means write to specified FILE instead of stdout.

Once done, you can verify the ISO image using following ls command as shown.

$ ls -l /home/tecmint/Documents/Linux_Mint_19_XFCE.iso
Create ISO from Bootable USB Using dd Command
Create ISO from Bootable USB Using dd Command

Create An ISO From A Bootable USB Drive Using Gnome Disks

Gnome Disks is a graphical tool used to manage disk drives and media in Linux. It is used to format and partition drives, mount and unmount partitions, and query S.M.A.R.T. (Self-Monitoring Analysis and Reporting Technology) attributes.

If you don’t have gnome-disk utility on your system, you can install it by running the following command.

$ sudo apt install gnome-disk-utility        #Ubuntu/Debian
$ sudo yum install gnome-disk-utility        #CentOS/RHEL
$ sudo dnf install gnome-disk-utility        #Fedora 22+

After successfully installing Gnome disk, search and open it from the system menu or dash. Then from the default interface, select the bootable device from the list of mounted devices on the left-hand pane, by clicking on it and click on disk options. Then click on Create Disk Image option as shown in the following image.

Create a Disk Partition Image
Create a Disk Partition Image

From the dialog window, set the name of the ISO file, its location and click Start creating. Then enter your password to open the bootable device and the process should start if the authentication is successful.

Create ISO from Bootable USB Using Gnome Disks
Create ISO from Bootable USB Using Gnome Disks

That’s it for now! In this article, we’ve explained two ways to create an ISO from a bootable USB drive in Linux. Use the comment form below to share your thoughts with us or ask questions.

Hey TecMint readers,

Exciting news! Every month, our top blog commenters will have the chance to win fantastic rewards, like free Linux eBooks such as RHCE, RHCSA, LFCS, Learn Linux, and Awk, each worth $20!

Learn more about the contest and stand a chance to win by sharing your thoughts below!

Aaron Kili
Aaron Kili is a Linux and F.O.S.S enthusiast, an upcoming Linux SysAdmin, web developer, and currently a content creator for TecMint who loves working with computers and strongly believes in sharing knowledge.

Each tutorial at TecMint is created by a team of experienced Linux system administrators so that it meets our high-quality standards.

Join the TecMint Weekly Newsletter (More Than 156,129 Linux Enthusiasts Have Subscribed)
Was this article helpful? Please add a comment or buy me a coffee to show your appreciation.


Leave a Reply
  1. Now, the downside of the Gnome Disks method is that it creates an ISO file that includes the free space (!), and if the free space is 1T, say, you’re looking at at least 45 mins of creation time, which is prohibitive not to mention that restoring such a big image takes somewhere around 1hr(!), while the user data is not bigger than 20Gs at the most.

    If only there was a method to create an ISO disk image without the free space!

  2. I had a utility called Systemback installed on Xubuntu 16.04 (and 18.04) which would also create an ISO to put on USB or SD card (I don’t recall if it was directly or using a usb startup creator disks tool like dd or usb-creator).

    Those systems were 32-bit… *Ubuntus now only come in 64 bit and I was given an older XP laptop that only ran 32-bit. So I pulled out that old USB adapter and SD card, and BAM, my old system installed on that old thing.

    Considering it’s a single-core Celeron and came with XP and has been out of support for just ages, that’s amazing. The Systemback on that SD gave the options of installing just the OS (and blank user) or also installing the /home folder from the previous install (which I did NOT do, as the drive was rather small on the old laptop.)

    • Dude! could be possible that you could share somehow that OS for old laptops? or some mirror link? Right now I’m on the same boat of trying to save& use a kinda like the one you mention. thanks :)

  3. Win To USB is a lightweight software that allows you to install and run Windows on a USB hard drive. An easy-to-use wizard code that provides a detailed guide to creating USB To Go USB drives.


      • @Yuri

        There is nothing to fix, the command is correct. If and of are command line options for the dd command, kindly read the manpage of the dd command.

        In this case, we are not creating a bootable USB drive, but creating an ISO image from a bootable drive already created.

    • @j

      I ask you to kindly read the dd man page to understand the meaning of if and of in the command, if what is explained in the article is not enough:

      $ man dd


  4. Can I use this method to say, boot a Debian-live.iso (text only NO DE) from a USB stick, install software; e.g, a windows manager + some apps, then use this approach to save that and the resulting file will be a bootable custom.iso?

    • Hi Moltke, No, a Live iso uses a squash.file that can not be modified without the special procedure of decompressing squash file – build OS – rebuild squash (very complicated). To build a custom OS USB build.iso with Debian or what I use Sparkylinux 5 to a USB stick,

      1. Gparted –> USB Stick = 1 partition ext4 & 1 partition swap (2-4GB usually).
      2. Make a deb or sparky live DVD, boot from DVD, and then insert USB stick 16GB at least.
      3. Install OS to /dev/sdX1 partition (X is identifying number for your USB stick).
      4. Customize your USB bootable OS.
      5. Use the above to create the iso file.
      6. Compress the iso with xz (it will reduce the size to about 1/2 in most instances).

      Hope this helps!

  5. Hi Aaron,

    Great Post! Thank you for sharing this informative post on creating iso from bootable USB in Linux. I am pretty with the content and It really works…

    Keep up the Good Work… Keep sharing…


  6. Perfect! Thanks!

    I needed to free up my 4G USB thumb drive to make a different flavor – live bootable stick (gonna try Antix) but wanted to keep the Mint19.3 ISO in case I need it again.

    I had deleted the original ISO download so I wanted to get it back off the bootable USB. I can’t believe the confusion in the comments here…

    It is clear which way the IF and OF are oriented and what the commands are intended to achieve.

    In fact, there are any number of google results about how to go from ISO to bootable USB but very few on going the other way, so THANKS again !!

    • @Kohn

      We do understand, many users are only familiar with creating a bootable USB using an ISO image but creating an ISO from a bootable USB. Many thanks for the useful feedback.

  7. Your USB Stick has ISO9660v Partition that is not a problem to make an iso from it! But the most Bootable USB-Sticks has a vfat or fat32 or ext2/3/4 formatted partition

    And Now ??

    This Instruction will not Work with formats other than ISO9660

    I have a 16GB USB-Stick with a bootable Linux Partition (Type 83) and need this as a bootable iso file

  8. Shouldn’t you provide the iso filename for if=... and the media for of=…? In the parameter definition, you say so but in the example, you do the other way.

    • @SEBI

      Check the heading, “2 Ways to Create an ISO from a Bootable USB in Linux”. We are showing how to create an ISO(/home/tecmint/Documents/Linux_Mint_19_XFCE.iso) from a bootable media(/dev/sdb1).

      • I had the exact same problem as sebi!

        I have an iso file of an operating system and have been wanting to create a bootable USB stick with it, and running into problems. After searching and following a few different sets of directions, I stumbled on your article. I did not read the title carefully and therefore followed the advice even though what I’m trying to do is the opposite.

        The article is good, but perhaps you might consider editing it to warn readers that this is NOT for creating a bootable USB from an iso, since I suspect it’s more common to want to do that.

  9. This will create an image of USB (.img actual file type) and not standard ISO9660 format iso file, you are just changing the extension name, and the size of the output file is equal to the size of the input USB drive, ie: if there is 300MB of content in the 2GB USB drive, then the output file is 2GB only!.

  10. Wanted to know how to make a USB bootable from a bootable ISO image that is booted without any problem using vmware/virtualbox.

    When I put this ISO image on USB stick it doesn’t boot at all. I tried many programs, many techniques and none of them worked.


Got Something to Say? Join the Discussion...

Thank you for taking the time to share your thoughts with us. We appreciate your decision to leave a comment and value your contribution to the discussion. It's important to note that we moderate all comments in accordance with our comment policy to ensure a respectful and constructive conversation.

Rest assured that your email address will remain private and will not be published or shared with anyone. We prioritize the privacy and security of our users.