I have a bootable persistent live USB running 18.04.4 on my macbook pro. From this session I want to create a FULL 18.04 installation on a different USB so that I can install and update software, etc. Keeping in mind I want to put the full desktop installation on this second USB and I want this new USB to be obviously bootable on my mac.

After searching and searching I can find no complete instructions on:

-- howto from the live usb session properly format a new usb so I can install 18.04 on it

-- I have a "Install Ubuntu 18.04 LTS" shortcut on my desktop -- should I be using this to do the install?

-- how to perform a FULL install to the new usb and ensure that it's bootable on my mac

-- how to ensure that the new full installation will allow me to install / update software

If anyone can please provide complete steps I would greatly appreciate it -- lots of pointers to resources on how to do this on a PC -- but I'm running on a mac and they discuss tools I do not have.

I keep running into issues where I can't update software because the device is "read-only'. I've tried to reference suggestions on how to fix that but all eventually say installing a full desktop installation on a usb is the way to go.

Thanks sincerely in advance for any help.

  • 1
    When you plug a second USB into your mac, does the Live session detect it?
    – user535733
    Feb 21, 2020 at 17:39
  • If I pull up the disk utility it sees it and when I insert it I get some sort of popup that stays something about USB but I've not been able to see anything other than that.
    – GR99
    Feb 21, 2020 at 18:43
  • Apologies I wasn't clear -- yes, I am booted on 18.04 via a persistent live usb. Yes, if I plug in a USB I get a pop up saying "USB Disk" and if I launch Files I can see the USB in the sidebar. This is while running 18.04.
    – GR99
    Feb 21, 2020 at 21:52
  • In the Try Ubuntu session, open a Terminal and run df -h. That will tell you how each disk and partition is labelled (usually /dev/sda for each disk, /dev/sda1 for each partition). You can usually tell which is which by the sizes ("oh, there is my 64GB stick"). Write down exactly which label corresponds to the USB drive that you want to install Ubuntu upon. Close the terminal. Once you understand which disk label points to your second USB stick, then start the installer. When you see a prompt or a drop-down menu with disk labels on it, then make sure you select the correct disk label.
    – user535733
    Feb 21, 2020 at 22:09
  • Thank you -- it's /dev/sdd1. I'm getting a prompt -- "unmount partitions that are in use?" -- it refers to /dev/sdd and /dev/sdb -- /dev/sdd1 (is the new usb) and /dev/sdb1 points to /isodevice and has 5.7G used -- I'm guessing that is the existing live usb. Should I unmount partitions on these disks? I only have the option of yes or no. I would think unmouting the live usb would be problematic or no?
    – GR99
    Feb 21, 2020 at 22:22

1 Answer 1


I was able to solve this with many thanks to @user535733 -- much appreciation.

First, I created a live bootable USB. Please NOTE: if you want to be able to make changes to your Ubuntu environment you will need to make a persistent live usb.

-- to create a bootable live usb that will not remember configurations or changes once you reboot -- follow this guide:


-- to create a persistent usb that will remember SOME changes when you reboot (like network config, etc) follow any of these guides -- note if you use the last one you will either need to buy the tool or compile it -- I bought it for $4.99...

option 1 -- How do you create a live persistent Ubuntu USB on a Mac that will boot to a Mac or PC?

option 2 -- https://apple.stackexchange.com/questions/285722/persistent-ubuntu-boot-usb-macos-sierra

the source is here if you want to build it yourself: https://github.com/SevenBits/Mac-Linux-USB-Loader/wiki/Using-Persistence-with-Mac-Linux-USB-Loader

2 -- with a live usb version, boot your mac using the instructions for either option above -- note if using persistent you need to follow the boot instructions to boot persistent

3 -- once your Ubuntu system is up, get networking going (wired ethernet is easiest)

Note -- you will see an Ubuntu installer on the desktop -- you will use this in a future step to install FULL 18.04 onto your new usb

4 -- insert a new USB into the system

5 -- open terminal and run df -h

Note which device is your new usb in my case it was /dev/ssb -- see comments from user535733 in the comments of this post for more helpful info

6 -- start the Ubuntu installer by double clicking on it -- if it asks to unmount partitions, let it

7 -- as the installer runs it will ask you to pick from a drop down which device you want the install to go to -- BE SURE you pick the new usb that you identified in step 5 above.

8 -- let the install go -- it will take a long time. I chose to install updates and complete drivers - pick what works for you.

Once complete power down your system, remove the original live USB (not the new one) and boot your mac by holding down the option key and pressing the power button. Once the boot loader comes up select the new full ubuntu USB to boot from -- it will take some time to come up -- be patient

9 -- post install note -- when I wanted to go back to my mac os the system kept loading a grub boot loader. I was able to get around this by resetting NVRAM (hold option+command+P+R keys and power up) see this Apple note: https://support.apple.com/en-us/HT204063

That's it -- I was able to create a FULL installed 18.04.4 LTS USB that will remember all the software I and and changes I made.

Again, many thanks to @user535733 for the help!

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .