I understand what the Plasma Desktop Environment is. But what is "atomic and transactional Linux"? What are the advantages to the alternatives? What other projects are similar? What is the motivation for this project in particular? Most importantly, why should I want to use it?
It's a glorified Live CD, with added "persistence" for user data. Updates are done by replacing the system install (which is readonly during normal operation, just like a Live CD) and rebooting, with an A+B mechanism enabling seamless updates during operation, as well as rollback if the new install fails. It's the modern "cattle not pets" approach to system administration: every system is running a well-defined ("atomic") Live CD equivalent, not something bespoke that's the unpredictable result of partial updates and/or edits on the running system.
Things like /etc are writeable, so you don't need to reboot for simple configuration changes.
You can run it just like always with all packages installed - it's just not recommended as the additional complexity on updates increases the risk that manual intervention is needed, and tooling is good enough that for a lot of stuff you don't really need it there. Like, toolbox or distrobox as podman based containers running in the host namespace (either as user or root), allowing persistent installation of debug tools, without having to reboot.
Linux distros that are updated with full system snapshots instead of package by package, similar to Android. The key difference is most of / is mounted read-only[0] and is only changed by distribution provided updates so you and the distro team always know exactly what's running.
> What are the advantages to the alternatives?
Greater control and stability since its essentially always running in a supported configuration. Easy roll-backs to a previous update if something goes wrong. You always know exactly what your system is running if you want to keep it in sync across machines (more useful in a server setting).
> What other projects are similar
Kalpa is a "sibling" project to AeonOS, which is atomic OpenSUSE but with Gnome (and other changes, which I'll get to). There's also the Fedora Atomic line of Fedora Kinoite and Silverblue (KDE and Gnome respectively), U-Blue, Bazzite, SteamOS, and more. I think most major distro lines have an Atomic variant at this point.
> What is the motivation for this project in particular?
For Kalpa specifically, it's to offer a KDE alternative to AeonOS. Originally there was just AeonOS, which was OpenSUSE MicroOS (an atomic version of OpenSUSE Tumbleweed) with GNOME installed. Aeon has diverged greatly from MicroOS though and I think it no longer uses it as an upstream. AeonOS also refused to support KDE[1], so Kalpa was created. Kalpa still uses MicroOS as its upstream and I'm not sure if there's any plans to change that.
> Most importantly, why should I want to use it?
I use it on my personal laptop because it lets me have all the benefits of a rolling distro (up to date packages) without the stability concerns. Updates apply automatically in the background and I know when I reboot I'll always have a working system available to me.
[0] /etc is mounted as an overlay FS so you can still make changes to it. /var, /usr/local, and /srv are also still user-writable. I think /mnt is too but I forget off hand.
[1] Aeon is generally anti-customization and does its best to only offer one way of doing things. This is to prevent configuration drift and reduce the maintenance burden per snapshot. GNOME also has a more regular release cadence, which makes it much easier to integrate than KDE (or so I've been told..)
[Maybe unrelated, but just occurred to me (some horror stories have prevented me from trying ZFS-on-boot in linux after Ubuntu botched it with their Zsys “adventure”).]
An atomic distro is one in which the updates are swapped atomically at reboots. They also go by the name of immutable distros. Only the "system" partition is immutable.
Most popular I would say is SteamOS followed by the Fedora variants (Silverblue, Kinoite) and derivatives (Bazzite).
They are still limiting in daily use, rough around some edges.
> Automatic Updates: Updates never touch your running system, only taking effect on reboot.
> Resilient: Due to the atomic nature of updates, if something goes wrong, the system will automatically roll back to the last known good working state
Plus, updates aren't the only thing that require reboots. Various config changes will need a reboot or at least require you to log out and back in. Even just adding your user to a group needs you to end your session for the change to apply.
But atomic versions as more target to desktops or containers where you need to have know working setup and when you upgrade you replace it by newer one..
So you dont update per se... You install the new version in a separated partition and boot into it the next time you restart.. Same with containers, you just destroy it and recreate with the new version..
If the new version fail you boot back to the old original version that is know to be working and have not being replaced..
The ideia is to ensure a known to be working system is always available..
# Terminology
1. Immutable: The core OS (/usr directory) is kept in "pristine" condition by disallowing modifications.
- Discourage installing packages or removing packages.
- well-tested (as most users are running the same OS with same package version)
- System upgrades are an entirely new immutable copy
NOTE: kalpa in particular, uses suse-microos tech called Transactional-Update https://documentation.suse.com/sles/15-SP7/html/SLES-all/cha...
# Atomic styles
4 mainstream models of immutable distros:
1. declarative-config: ALL your system configuration in a config file eg: package versions, network config, user accounts and so on. eg: NixOS, BlendOS
2. OSTree-based: You use cloud/container (OCI) technology (eg: docker files) to layer upon existing layers (eg: pre-baked system images). eg: fedora's atomic spins, vanillaOS, endlessOS. So, fedora coreOS is the base layer -> atomic spins like silverblue/kinoite layer desktop packages like gnome/kde etc.. -> the infamous gaming distro "bazzite" layers gaming packages like wine/steam/drivers etc. and so on.
3. Btrfs-snapshot-based: You take a btrfs snapshot of your root partition before upgrading, so that you can boot into it if the upgrade fails. eg: suse-microos family (kalpa belongs here), chimeraOS
4. systemd-mkosi based: You essentially "curate" an entire OS filesystem in a directory using mkosi and deploy it as an immutable disk image. eg: kdelinux
NOTE: systemd-mkosi is the vision of systemd maintainers as mentioned here: https://0pointer.net/blog/fitting-everything-together.html . There's a whole bunch of system features in development to achieve this ideal.
Most of these distros (except btrfs-based) simply use the A/B root system. They just maintain two root partitions/images, put any upgrade into the "other" partition, mark that as live and the current partition as backup. If the boot into the new partition fails, they just boot into the backup partition and just wait for next upgrade.
As they don't allow usage of system package manager, you are supposed do package management at user level. For gui apps, you resort to flatpak. For other utilities, you usually pick homebrew or language-specific tools like cargo, pip/npm etc..
# The magical tool called Distrobox
This runs containers in userspace and tries to integrate them into your system as much as possible.
A lot of software development requires system level services or shell access or install dependencies etc.. You obviously can't do that on host, as system package management is essentially forbidden and half the point of immutable distros is to keep the host "clean".
So, you create a container and do all your development in there. If it gets too dirty, you just delete it and create a new one.
Personally, I use an arch container for development, as it has all the bleeding edge packages and the convenient AUR too. vscode (from flatpak) supports connecting to containers using official remote extension. I also run a media server inside it. You can also install any system packages or cmdline utilities you want inside it (eg: codecs, ollama, etc..).
# Why kalpa over others?
- Great KDE polish that suse is known for
- btrfs tech is mature and was already used in suse for years, the atomic system is very simple to understand and you can just pick the snapshot you want at boot menu.
- Despite being immutable, customizing the system (eg: installing a driver, kernel modules, firewalls etc. ) is easy too.
- just enter a transactional update shell
- this creates a new mutable snapshot of the current system and chroots into it
- run all the commands you want inside the shell. eg: install/remove packages, enable services etc.
- exit shell. This will mark the transaction as success/complete and set the snapshot as live for next boot.
- Updates are fast/tiny, as they are just routine rolling release updates from tumbleweed repos.
There are some problems too:
- single maintainer
- less popular, compared to alternatives like fedora-based atomic spins.
- It's based on tumbleweed, so, you get lots of tiny updates (almost daily). Fedora based, for example, have weekly/bi-weekly updates.
- still in alpha stage (but once you set it up, it's rock solid).
- Immutability is still a new concept, and flatpaks are rough around the edges. Expect bugs. Mutable/traditional distros are still easier to use, as that has been "the way" forever.
MicroOS and its derivatives are all based on Tumbleweed. MicroOS was intended to be used for container workloads. Aeon grew out of that with a GNOME desktop, Kalpa a KDE desktop. Because they were focused in a way Tumbleweed is not, they are a more opinionated distro. On the other hand, Tumbleweed is a rolling distro that wants to be all things for everyone.
I guess you get the atomic system, but with Tumbleweed you get snapshot backups anyway.
One of the main advantages of Tumbleweed is the extensive testing pipeline. I'm not sure how a derivative would be able to offer a similar experience
"note: These installation instructions will be changing, with the Beta release of Kalpa"
A bit rough around the edges - so probably unfair to publicise too prominently yet.
[EDIT]
Oh, and I had a lot of problems installing Kalpa (from the submission) - all which I got fixed by using ChatGPT.
The more I think about it, I don't even use Pacman, I just use the other tool that comes with Endeavuor, which is a face to Pacman and probably shields me from doing doofus things. Pacman is easy to screw up an update with.
Just works
Ofc the distro can be installed for free. Owning the business sets you back some $6 billion.
I admittedly only used it on a 13 year old gaming computer and couldn't get the GPU drivers because... you know containers.
This is something trivial with a regular install. (Especially with LLMs to assist)
I want to like Atomic, but it feels like an Apple-like regression in computing.
The secret is that all your power is within a distrobox container. All my dev tools, Emacs are in an Arch Linux container.
Why would any distro want to support a tool that intentionally breaks things? Ventoy could just boot ISOs without messing with them and everything would work fine, but the developers insist on injecting garbage.
Perhaps ventoy doesn't like SuSE.