Comment je genere un truc par defaut qui va me reprendre mes partitions actuelles et les packages déjà installés?
Pour le partitionnement, si j'ai bien compris, tu dois passer par Disko

https://github.com/nix-community/disko

https://wiki.nixos.org/wiki/Nixos-anywhere

# disk-config.nix
# Example to create a msdos partition
{ lib, ... }:
{
  disko.devices = {
    disk.disk1 = {
      device = lib.mkDefault "/dev/sda";
#      type = "disk";
      content = {
        type = "table";
        format = "msdos";
        partitions = [
          {
            part-type = "primary";
            fs-type = "btrfs";
            name = "root";
            bootable = true;
            content = {
              type = "filesystem";
              format = "btrfs";
              extraArgs = [ "-f" "-O block-group-tree" ];
              mountpoint = "/";
              mountOptions = [ "compress=zstd" ];
            };
          }
        ];
      };
    };
  };
}