Re: Dropping gzip-compressed substitutes

["Ludovic Courtès" <ludo@gnu.org>]

Hi!

Thumbs up for the progress made!

Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:

> 3. Come up with a Guile script that is able to
>
>   a) Strip gzip-related metadata from the .narinfo guix-publish metadata
>   files
>   b) recompute and update their 'Signature' field.
>
> 4. Finally, 'rm -r /var/guix/publish/gzip' and free about 6.5 TiB of data.

As discussed on IRC, I’m skeptical about this because:

  1. It requires the development and testing of a custom tool that’s
     easy to get wrong—e.g., it removes a gzipped nar for something that
     had nothing but gzip available, etc.

  2. That code would have to run with privileges that give it access to
     the signing key on berlin.

  3. Those 6.5 TB are an initial constant factor; growth of the storage
     requirements going forward probably matters more and
     <https://issues.guix.gnu.org/53901> will give us more flexibility
     on that.

I like Chris Baines’ idea of decoupling nar distribution from nar
building.  If we want to keep nars long enough so that ‘time-machine’ is
usable, then storage requirements will keep growing.

Perhaps that means we can regularly copy nars “elsewhere” for long-term
storage, using nar-herder, rsync, or whatever.  The machine that stores
nars long-term has low requirements compared to the build farm because
we don’t need to trust it for anything other than storage.  If that
makes things easier (and financially viable), a VPS is good enough.

Thoughts?

Ludo’.