Switch cache.nixos.org to ZSTD to fix slow NixOS updates / nix downloads?

[yorickvP]

Slow cache.nixos.org

I’ve reported this problem at #infra:nixos.org Matrix room, but haven’t heard from them. Following is the video demonstrating the problem: https://asciinema.org/a/506447 Following is the output from the diagnostics script: http://ix.io/40Rt From my observation, it seems like if the file is not cached at local cache.nixos.org server(s), then the fetch from origin is slow. Once the file is cached on cache.nixos.org server, it downloads on the client just fine. And from my use it seems like I’…