I have used Pi Imager to write Ubuntu Desktop to my SD card. When I try to boot from it in my Pi 400, I get the following error:

[50B]: Failed to remount '/' read-only: Device or resource busy
systemd-shutdown[1]: Failed to finalize filesystems, ignoring.

and then the Pi shuts down. The first time I booted, I also saw Ubuntu logo and the spinner icon but I can't remember if it was at the very beginning of the boot or just prior to the shutdown (I suspect the latter) but it is no longer showing.

Since I was able to boot into Raspbian from another card, I inserted the Ubuntu card through an USB card reader and both partitions created by Pi imager on that Ubuntu SD card are visible, readable and writable: I was able to create a backup copy of firstrun.sh and then remove it (as I suspected that it might be causing issues and I also wanted to confirm that the card is writeable).

fsck does not throw any errors for either partition so it looks like filesystem is not corrupted.

What could be the reason the system fails to boot?

1 Answer 1


I was able to find the source of the issue thanks to these two posts from Pi's forums:

https://forums.raspberrypi.com/viewtopic.php?f=28&t=58151 https://forums.raspberrypi.com/viewtopic.php?f=28&t=248968

It turns out, I flashed the image on 32GB microSD card which I put into microSD-SD adapter which I then inserted into SD card reader "port" in a laptop and even though all files required for boot seemed to be there, apparently something in that chain of adapters/readers didn't fully support SDXC standard needed to flash the image on this 32GB card correctly.

I re-flashed the card using Pi Imager and microSD reader inserted into USB port of Pi 400 and Ubuntu booted fine.

Now I have an issue with the desktop environment which I link to below just in case someone who solved the boot issue thanks to this also experiences the same issue with desktop environments on Ubuntu on Pi in general:

Ubuntu desktop environments freezing on Pi 400

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.