For once I feel a little out of touch after I took a bit of a break from following the news to focus on studying, and suddenly everyone is talking about immutable distributions. What are they exactly? What are the benefits and the disadvantages of immutable systems?
Have you used Android? Has it ever failed an update or break due to an app install in a way that can’t be fixed by uninstalling it or factory resetting? Android is an immutable Linux OS. Its system files are stored on a read-only partition. They’re only mounted read-write during update. (That’s a lie, this is no longer the case, but it used to be, these days there are two partitions and the whole inactive partition is written during an update, or a volume snapshot pretending to be a partition is created and then merged, but functionally it’s consistent with the lie.) Apps are also stored in read-only form. One implication of this is that upon update, the partition/files you want to update are always in a predictable, unchanged state. That guarantees successful updates. It also allows trivial diff updates. The other implication of these facts is that you can always delete the mutable part of the OS, where your data and the apps’ data is stored, and you’ll always end up with a clean, working OS in a factory state. On Android you can also do this per-app by tapping “Clear data”.
Wouldn’t it be nice if you desktop or server behaved like this? Some folks think so and are trying to implement it.
There are few disadvantages beyond having to change how some systems work to accomodate this model. There’s typically more space wasted.
With tbis update system, I don’t understand why you can’t use your phone while doing it.
You can. Google pixel updates are just a reboot. Sadly many OEMs don’t do A/B updates, like samsung, so your phone can’t be used while updating the system partition
It’s worth mentioning that they often do this to reduce flash size, i.e. save 💰. Virtual AB was introduced to help with this but it’s relatively new. With it, there’s no need to reserve the space for 2x system partition. The needed extra space during update is taken from /data and released post success. There’s also a compressed virtual AB scheme now which helps reduce the space needed from /data to enable really space-crippled devices like CCwGTV and other Android TV things like Sony and other TVs.
the whole concept of immutable is focused on stability and safety of your system – yes, it is still possible to break an immutable distro, but it’s a LOT harder and takes some actual effort – there’s also a few concepts wrapped up into the “immutable” phrasing:
- immutable filesystem – the root filesystem is set as read only, updates are queued up and applied during an upgrade (some distros require a reboot, some don’t)
- VanillaOS keeps two copies of the root system (ABroot), upgrades the inactive copy and then swaps them out
- NixOS has everything defined in a master config file and keeps an archive of previous generations of the config file allowing you to boot into whichever generation you want
- atomicity – updates are applied individually and checked, if the update breaks then it’s reverted to the previous working state (ie. you are never left with a borked system)
- containerized apps – user space apps isolated or sandboxed in some way like Flatpaks or Docker containers or OCI so if they break, they don’t take anything else down with them
- declarative systems – the whole system (and packages and configs) are defined (declared) in one master config file – back up that config file and if something happens to your system, you just need that one file to do a full rebuild (or make an identical copy of your system on another computer) – NixOS and GNU Guix are the two more well-known in this space
- EDIT: minor side-effect of this is you can easily tell exactly what packages are installed on your system at any given time – no hunting through
historyor trying to remember what you installed last month when you were testing out video players
- EDIT: minor side-effect of this is you can easily tell exactly what packages are installed on your system at any given time – no hunting through
- immutable filesystem – the root filesystem is set as read only, updates are queued up and applied during an upgrade (some distros require a reboot, some don’t)
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I love Universal Blue.
It’s OCI cloud image based Fedora Silverblue/Kinoite/Serica with extra steps/batteries included.
“The reliability of a Chromebook, but with the flexibility and power of a traditional Linux desktop.”
But also probably an easier way for
Nvidia Fedorausers to game on Linux:Easily roll back deployments or 📌 one and rebase to something else easy peasy. (So many different choices) Test betas with no fear!
I’ve actually been gaming on Bazzite for two weeks now:
Jorge’s Blog:
Media:
- High-Tech Lo-Life on YouTube:
- “As Seen on TechSpot”
- “As Seen on GamingOnLinux”
- “As Seen on tom’sHARDWARE”
If you wanna simply make your own image to share with friends/family:
Universal Blue isn’t a distro. It’s more of a reimplementation/enhancement of
ImmutableOCI Cloud Based Images of Fedora.uBlue is great. After using Fedora Silverblue for more than a year I used it to have the same OS on my laptop and desktop. It’s works great and is quite simple if your already familiar with building containers. But the constant reboots and rebuilding an image taking minutes made me switch to NixOS.
The advantage of uBlue over NixOS is imo that the former is configured like any other Linux by placing files in the traditional file system hierarchy (e.g. binaries in /usr/local/bin). NixOS throws most of that over board and makes use of it’s own configuration language and package manager. Getting started with uBlue is definitely easier, while NixOS is a time-consuming rabbit hole (not that uBlue isn’t…). For a tiling wm setup I definitely think NixOS is the better choice, since changing core system components is quicker.
People literally made a distro spin that’s dedicated to rolling back nvidia drivers.
Classic nvidia moment right there.
But Universal Blue does look very interesting, I need to try and use it with distrobox and see if I can hit any walls that aren’t there with a classic setup.
####For an in the wild example, Steam Deck.
Steam Deck runs Steam OS, which is a heavily customized version of Arch Linux by Valve. But unlike normal Arch installs, Valve has locked the System partition(/) to read-only.
The reasons they’ve done this is two fold. First, there’s actually two copies of the system partition. The reason for this is that when an update is downloaded it’s actually written to the other partition, not the one you’re currently using. This way the update happens in the background, and then you just need to reboot for it to switch partitions and do some house cleaning. What this means though, is that any changes you might’ve normally made to the system partition, disappear, as they are now on the other partition you aren’t using. So if any changes you make won’t matter, not much point in letting people make them in the first place. Using Flatpaks, any applications users install would instead be stored in the user partition, and never touch the OS itself.
The second major reason for doing this, is consistency. If people are discouraged or blocked from modifying the system partition, then any bugs or issues that crop up are, 99% of the time, Valve’s fault. And because of that, Valve can more easily diagnose and try to reproduce any reported issues, because theoretically, the user’s Steam Deck should be configured exactly the same as one at Valve HQ. All that’s needed is for a user to report what they were doing when they encountered the issue, and Valve can follow those same steps and hopefully encounter the same issue, get detailed logs, and hopefully quickly push out a patch as needed.
And that’s one version of Immutability. Valve doesn’t go the full nine-yards here, just enough for their use case. In other Immutable Distros, versioning is taken even further, where you can control multiple versions and reset the OS state on the fly as needed, keeping any changes to a minimum and in controlled sand boxes. There’s a ton of use cases for these, but the most obvious benefits are for enterprise and mass-market solutions, where a single configuration is multiplied across a large amount of servers, or end-user devices, allowing for easier diagnoses of issues and pushing of patches. For end-user clients especially, if they aren’t expected to be customizing the OS to begin with, it makes support much easier for IT.
For your average Linux user, the benefits aren’t as large, as you’ll often want to be able to tweak things to your liking. But your Average Joe that just wants a computer that can surf the web and install some apps that can be found as Flatpaks, an immutable OS that they can’t easily screw up is a plus.
