Adding NixOS entry to libosinfo - recommended resources?

I’ve opened a pull request to add NixOS entry to libosinfo. The goal is to have libvirt’s virt-manager automatically use VirtIO devices when installing NixOS from ISO image. Part of the OS entry is minimum and recommended amount of RAM and disk space. Currently there’s:

Minimum: 1 GiB memory, 10 GiB storage
Recommended: 4 GiB memory, 20 GiB storage

Do you think that’s about right? Would you change anything else about the entry?


Why are you adding both e1000 and virtio-net ?

Not sure, I’ve copied the list from other recent linux in the repository, my understanding is that those are devices that are supported.

@jtojnar This is what we need for NixOS image missing from GNOME Boxes · Issue #56427 · NixOS/nixpkgs · GitHub :sparkles:

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This is the only info I could get about minimum requirements from the installation docs for virtualbox NixOS - NixOS 21.05 manual

Base Memory Size: 768 MB or higher.
New Hard Disk of 8 GB or higher

It’s surprising that we don’t have any numbers, that I can find, describing stuff like minimum and recommended specs in memory and storage.

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For desktop use (picturing a user firing it up via GNOME Boxes), I’d say it should

  • have enough space for the system, including $some mass-rebuilds later (around 3.5GiB with plasma5 desktop currently, so 8GiB is alright if some=2)
  • have enough RAM to evaluate/build a new system. According to experiments with ulimit -v, nix itself needs about 700MiB for this, so adding the kernel, desktop environment and such I suspect we’d need at least 1.5G.

commands I used:

  • nix-build '<nixpkgs/nixos>' -A --arg configuration '{ services.xserver = {enable = true; desktopManager.plasma5.enable = true;}; boot.loader.grub.device = "/dev/dummy"; fileSystems."/" = { device = "dummy"; fsT ype = "ext4"; }; }'
  • nix path-info -S ./result
  • ( ulimit -v $((100<<10)) ; $systemBuildCommand ) increasing in 100MiB increments

Right, so that’s 1.5GiB RAM + 8GiB disk for minimal? What about recommended?

When installing in virt-manager the recommended values are offered by default. Setting them below the minimum values doesn’t seem to do anything so not sure if the minimum has any effect. Dunno about Gnome Boxes, it’s currently stuck on “Downloading media…”, will report if it moves on.

I’d suggest doubling the minimal values. I have no solid justification for it though :slight_smile: