Be warned; your hard drive may file for a divorce after a few years of daily-driving NixOS. It is both a blessing and a curse:

  $ smol@computer ~> du -hcs /nix/store/
  257G    /nix/store/

I'm so sick of this claim. Nix allows you to keep old versions of things installed, but you certainly don't have to.

When I switched from Debian to NixOS a few years ago, I installed it on a separate subvolume, and it ended up taking almost exactly as much space as Debian did (about 12 GiB with gnome and everything else). And really, what would you expect? It's nearly all the same code, just organized differently in the filesystem.

P.S., you can check the store usage of the current system profile with `nix path-info -Sh /run/current-system`.

You... do regular GC, right?

I have 45G, and this computer is more than two years old

I have multiple flakes and a lotta CUDA drivers. In fairness though, this is after a few months of no manual GC. I think nix-collect-garbage could bring it down to ~120-150gb.

It's totally worth the stability, but maybe not the best choice for the storage-constrained.

EDIT: According to nix-tree my current generation is only 45gb right now.