[dwohnitmok]

This is probably in part explained by the sheer size of nixpkgs. It's the largest and freshest (i.e. with the most up-to-date versions) package repository among Linux package managers (see https://repology.org/repositories/statistics/total).

Unlike Arch it also is not a rolling release package repository and has both unstable and stable branches that it needs to maintain (along with different versions for each). In fact, the NixOS cache keeps every version of every package that has ever been built and stored in the cache so that binary versions of all historical package versions are available.

Finally it also includes packages for MacOS binaries as well as Linux ones.

I'm frankly surprised it actually costs as little as it does given that it's using pretty expensive S3 storage for everything.

[ghuntley]

the cache also stores the source code used to create the build. there’s been numerous cases where upstream code has been deleted on GitHub or elsewhere then rescued from nixcache.

[0cf8612b2e1e]

What percentage of the total repo is source code? I would think the compiled artifacts could be tossed at a moment’s notice, but would not want to lose the source.

[SkyMarshal]

I wonder if there’s a more cost effective storage option besides S3.

[klysm]

S3 is definitely not in a great spot on the cost effectiveness axis, but it wins on a lot of other axes