Fixing boot problem with Ubuntu Mate installer

My goal is to put both OS installers on my USB and install Ubuntu Mate on my PC. Now nothing happens when I boot my PC even starting from external device is enabled at the first step in BIOS.

Here are steps what I've done:

  1. I created two primary partitions on my USB. (Is it right that primary partitions are required in my case? I am asking because I am not sure...)

  2. I downloaded Ubuntu installer and performed sudo dd if=ubuntu-mate-20.04.3-desktop-amd64.iso of=/dev/sdb1 status=progress

  3. I assigned boot (I am not sure whether it's required but I've tried) flag to /dev/sdb1.

What am I missing to successfully boot Ubuntu installer from USB?

P.S. Earlier I had just Ubuntu (not Mate) on my USB and 1 partition written via Balena Etcher and everything worked fine.

dd writes to block devices (/dev/sdb) not partitions (sdb1). Step 2 is wrong.

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Welcome to the community, EmilySeville7cfg.

You have to try Ventoy from

it will save you from inventing bicycles in multi-boot installation media creation.


I have done similar things installing 5 distributions on an external SSD via a USB connection.

For two distributions you don’t need to work so hard with partitioning since the installer will do that for you.

Once the first distribution is installed, you install the second distribution “alongside” the other. The Ubuntu distributions and others will give you that option, and the installer will divide up the partition and install the boot loader.

Key point here is where the boot loader gets installed. Usually, there is a selection to install the boot loader on the same device you are installing the distribution. However, some distributions will default to putting the boot loader on the main drive. So you might be on your Windows PC working from a live Ubuntu Mate USB stick installing to another USB stick or external SSD, but the boot loader is placed on “sda” for example (your main Windows drive) and not on the external SSD or USB. In this scenario, the boot loader is on the wrong drive and the installed distributions will not boot.

If you want to install manually, create 3 partitions. The one boot/efi partition and the two partitions for each distribution. I don’t create Swap partitions preferring a Swap file or no-Swap since I have a lot of RAM. Then when you start the installation you install to each partition accordingly. There are a lot of videos on YouTube that show how to accomplish this.

Again, remember that the boot loader needs to go on the same drive as where the distributions are installed. Otherwise, when you select that USB, there won’t be any instructions of what to do and nothing will boot.

I hope I made this clear and succinct but like I said, there are many YouTube videos that do a better job explaining all the nuances. I attached a link to one showcasing Mint and Ubuntu.

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What do you recommend to use instead of dd? I prefer do everything from terminal. :slight_smile: