[Nix-dev] What happens when installing NixOS?

[Eelco Dolstra]

Hi,

Clemens Tolboom wrote:

> I'm trying to install NixOS under qemu (686) according to
> http://nix.cs.uu.nl/dist/nix/nixos-unstable-latest/manual
> 
> Running the ISO is fine, but after downloading the packages
> nixos-install starts compiling (the source install) right?
> 
> Two questions then
> - How low takes "cross finger" apox.?

It depends on download speed and the configuration (e.g. if you enable the X
server it has to download many more packages).  I don't have any recent timing
info, but I guess it's on the order of 15-30 minutes or so for a basic install.
 Of course, in qemu it can take quite a bit longer, especially if it does need
to build a lot from source.

> - Is it possible to do a binary install? This would be nice for first
> impressors I think.

It *is* mostly a binary install.  As always, Nix in principle builds from source
(Nix expressions) but it downloads a binary if one has been registered through
nix-pull.  The installer does a nix-pull on the Nixpkgs channel, which contains
most NixOS system packages.  There are a few missing, though, so we should add
those (I think in particular there are some dietlibc or klibc-built packages
that are not in the channel).  Furthermore, any needed store path that's in the
Nix store on the CD is copied directly from the CD.

The channel contains many fewer prebuilt packages for x86_64, so there an
install will take quite a bit longer.

-- 
Eelco Dolstra | http://www.cs.uu.nl/~eelco