Prerequisites - What You Need

  1. A USB drive with 4GBs of capacity or higher – Pen Drive >= 4 GB size
  2. Ubuntu Desktop OS – Official Ubuntu Download Page
  3. Etcher app – Official Etcher Download Page
  4. iMac or laptop running macOS
  5. sudo access permission as required
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Before continuing this tutorial, please read the Important Checklist and Troubleshooting section at the end of the article. It consists of common mistakes and issues that may slow you down the road. It can save you time searching for solutions on the internet.

Step 1: Erase and Prepare the USB drive

  • Insert the USB drive into the port. Make sure the drive is detected and functioning properly without any warnings.
  • Next, hit ⌘ + Space to open up Spotlight search on your macOS. Search for Disk Utility and open it. Alternatively, you can also open it from Applications > Utilities.

Disk Utility should detect and show your USB device in the External category on the left panel. Confirm your USB device by cross-checking details like its Capacity, Name and Connection.

  • Select the USB device from External. Find and Select the "Erase" option from the top toolbar.
Don't botch or panic at this crucial step. Selecting the wrong drive can cripple and delete everything on your disks.

A dialogue box pops up before proceeding to the format operation.

Check and Verify Before Erase
  • Select "Format" and change to MS-DOS (FAT) or Mac OS Extended (Journaled)
  • Select "Scheme" and change it to GUID Partition Map. If the option is disabled, leave it as it is.
  • Now, check everything and hit "Erase" to start formatting the USB drive.

After a successful format, you should see something like this. The USB device is now ready to use.

Don't Eject or Remove the USB drive yet. Just hit Done

Step 2: Download, Install and Run as sudo – Etcher app for macOS

💡
Etcher by balena.io (resin.io) is a GUI standalone app for Windows, Linux, and macOS that flashes OS images onto USB drives and SD cards.
  • Download the latest macOS version of the Etcher app from the official page.
BalenaEtcher Website

After downloading the macOS version of Etcher, you should have an ~80MB dmg file with a name similar to balenaEtcher-x.y.z.dmg.

  • To install Etcher, double click the .dmg file to open it. Drag the app icon to the Applications folder to sync and mount the package. In case of permissions, work accordingly by entering your user password.
Drag and Drop
  • By default, newer macOS versions block apps from unidentified developers. To solve this same issue with Etcher, click "Open Anyway" in the "Security & Privacy" panel of System Preferences. Click the lock to save your changes.
Always enabling "App Store and Identified Developers" is a bad habit as it makes your system vulnerable to potentially dangerous apps in the future.
Lock to Save Changes
  • Next, to run Etcher with sudo permission, open up the mac terminal from Spotlight search (+ Space) and get ready for some bash commands.
  • In your terminal, type:
    ~ cd Applications/balenaEtcher.app/Contents/MacOS
    This is where the Unix files of balenaEtcher reside that need to be run as sudo. To do that, type:
    ~ sudo balenaEtcher
    (prompts for sudo password)

Now, you should be running Etcher with sudo access.

Etcher Screen

Step 3: Convert and Flash OS Image

By now, I assume you have already downloaded the ISO image of Ubuntu Desktop from the official page. We need to convert the downloaded ISO image into a DMG file with the help of hdituil, an inbuilt macOS utility.

  • Open up mac terminal and convert your .iso into .dmg with this command:
    ~ hdiutil convert /path/to/ubuntu.iso -format UDRW -o /path/to/target.img
    macOS puts the ".dmg" extension on the output file automatically.
  • Now, using the Etcher app,
    Select Image > Navigate and choose the recently converted Ubuntu .dmg file. Look for it first in the Downloads folder.
  • Select your drive and ensure it is set to the target USB device prepared in Step 1. Etcher should detect the inserted USB device. If not, find solutions in these resolved GitHub issues of Etcher.
  • Check everything one last time, and click "Flash!"
    Enter your computer password and initiate the flashing process.
Flash!

Wait for the operation to complete successfully, then safely eject the USB device after getting something like this.


Congrats! You have successfully created the latest Ubuntu Desktop OS Bootable on your USB device and are ready to go.


Important Checklist and Troubleshooting

  • Make sure the USB drive is not corrupted or malfunctioning. Some old USB drives may look fine, but their clusters could be crippled within the drive – resulting in unknown and vague errors during the process like below.
Use Another USB
📔
Your USB drive capacity must be at least 4GB. Having more size or space doesn't speed up the process – that's just a myth. However, USB drives with a 3.0 interface being faster than USB 2.0 interface drives is not a myth. Use the latest USB version available to you.
  • Ubuntu has 4 main types of OS distributions, viz. Ubuntu Cloud, Ubuntu IoT, Ubuntu Server and Ubuntu Desktop. In general, we use Ubuntu Desktop as the main OS for our go-to option.
  • We need sudo access for this tutorial because of the application Etcher that we used for flashing. Without sudo access, the Etcher app will create problems like the one reported in this GitHub issue.
Github Closed Issue
  • At the end of the successful flash, macOS may even warn you with errors like The disk you inserted was not readable by this computer. Don't select "Initialize". Select "Eject" and remove the USB device. If you already pressed Initialize, no worries – as long as it works, life goes on.
Thank you for reading to the end of this article. If you faced any issues, feel free to ask for help in the comments!