I’ve been curious about NixOS for quite some time. Reading about it I couldn’t see how the config sharing capabilities, setup, or rollabck would be better than Arch and sharing the list of installed packages, using downgrade or chroot.
So I decided to run NixOS in a VM and I’m still confused. An advantage I can see for NixOS is its better use of cores and parallel processing for packages install.
It’s clear that I’m missing something so please help me understand what it is.
One issue with rollbacks Arch has is that there’s basically only up to three valid configurations available at any time. These are your current system configuration (oldest state), upstream repositories (newest) and your local database copy (somewhere in-between, though all three states can be identical, e.g. straight after Syuing). By definition, you can’t convert your system configuration back to an older one because it’s the oldest one of the three already. What you can do is mix your current oldest configuration with packages from the cache, older or newer doesn’t actually matter. But you’re not getting back the old state really, you’re creating a new one that’s different from Arch’s repository.
A configuration on NixOS includes all exact package versions and their exact configurations. No exceptions.
If you actually need these guarantees is a different question. I used Arch for 15 years and never had significant issues. I switched to NixOS instantly after trying it on an old notebook and immediately recognized that the whole approach suits me so much better that I switched almost all machines over by now.
Very nice explanation. I also recognize this point for NixOS.After reading so many comments, they all confirm what I’ve read before and I may realize that my real problem is already having a stable system which means not being in need for some “advanced” recovery options. That being said, I’m still curious and will continue testing NixOS.
Not that I really have too much spare time but when I do I enjoy learning and tweaking NixOS. With its current development state, things are changing a lot so it can keep me busy for months. That’s probably what I was mostly looking for: another toy to play with. Will see if I actually switch to NixOS at some point. Thanks again for your feedback.