AMENDMENT Ubuntu 24.04 cannot install onto NVMe, at all, no matter what.

I tried it with a non-switched PCIe adapter, & it still couldnā€™t work.

Sorry I got it wrong, before.

Now Iā€™m working to discover if 25.10 can install to NVMe ( in spite of Lubuntuā€™s broken build-essential package, & the idiocy of Lubuntu telling us to file bug-reports in the Ubuntu One ( or whatever ) system, but that system not allowing that Lubuntu is a tracked project, so thereā€™s NO bug-reporting place for it. Idiocy. ).

Iā€™ll update this again whether it works or not, so you donā€™t have to do these stupid experiments to discover the fundamentals.

The performance-difference is sooo spectacular, that the engineers who wouldnā€™t include NVMe on the board-itself ā€¦ cannot be considered loyal to the potential of the devices theyā€™re engineering, tbh: they essentially ā€œCeleronā€™dā€ the things by making them use microSDXC, which ā€¦ not my values )

TL;DR:

IF you use Geerlingā€™s rpi-clone tool, THEN DONā€™T name your new root partition, let it do all the config by UUID,

AND if you have NVMe on a dual-device board, through a PCIe-switch chip, then your ONLY option is to boot from RasPi OS, because Ubuntu 24.04 LTS simply wonā€™t work through that: they configured the kernel to not be capable of it.

( didnā€™t bother trying 25.10, because on the destop, Lubuntu 25.10 CANā€™T INSTALL build-essential PACKAGE, so that breaks EVERYthing for my learning-programming machine, & I need both to be using the same OS, version-included, so I donā€™t get driven mad by UX-inconsistencies : )

This took waaay too long to figure-out, so Iā€™m putting it here for others, so you donā€™t have to bash your brain against the damn wall, like I did.

Geerlingā€™s rpi-clone tool, available from geerlingguyā€™s github,

# Install rpi-clone.
git clone https://github.com/geerlingguy/rpi-clone.git
cd rpi-clone
sudo cp rpi-clone rpi-clone-setup /usr/local/sbin

# Clone to the NVMe drive (usually nvme0n1, but check with `lsblk`).
sudo rpi-clone nvme0n1

has a gotcha: if you name the new root-partition, then it wonā€™t be able to mount it, in my experience.

Once named, that root-partition canā€™t be mounted when booting from NVMe, by /dev/nvme0n1p2, not by LABEL=whatever. ( didnā€™t try UUID mount )

You need to have it identical in your linux-kernel cmdline.txt ( which is in your /boot/firmware/ dir, aka your 1st-partition ) and in your /etc/fstab ( which is in your 2nd partition ).

That took ages to learn, too.

Let the rpi-clone util have NO name for the new root partition, & then itā€™ll correctly give UUID identifiers to both of those files, for your new root.

Then itā€™ll work in Raspberry Pi OS.

However, nothing one does can get Ubuntuā€™s 24.04 LTS to boot from dual-device/PCIe-switched NVMe adapter/ā€œhatā€: apparently Ubuntu pruned-out the kernelā€™s ability to work through a PCIe-switch, breaking all dual-NVMe-adapter-boards from being able to work.

( updated-system is current @ 2026-04-02, in case they update it in the future )

Iā€™d wanted to someday switch to BTRFS raid1, but ā€¦ thatā€™s impossible, unless remaining in RasPi OS, which I donā€™t want to do, because too many things consider Ubuntu to be the only default-config.

As Torvalds identified: itā€™s hell to make an app work with multiple distros, due to too-little being standard between them all, hence the ā€œjust do Ubuntuā€ paradigm thatā€™s substituting for app-developerā€™s standardā€¦

( & snaps/flatpaks are usually x86_64 only, ttbomk, so that doesnā€™t help, either )

Yeah, I know, Archā€™s got a Rpi4 ( or greater ) version, & yes, Iā€™ve tried it,

but I really want to stop doing sysadmin, & just do learning Haskell, THE programming-language for developing oneā€™s ability to think & to prevent-bugs in programs, if done correctly.

( no side-effects-distributed-throughout-the-entire-codebase, pure-functional, & type-level programming all contribute to that )

May you not hit all the damn corner-cases in the world,

_ /\ _