Hi Guix, First, I'd like to apologize for not having taken the time to answer those who helped me on a previous guix performance issue (with containers), the reason is tied to the topic of this email: the store has eaten all the space of my server, and solving that takes precedence over everything else, because no space == no services.
So, I need to clear some space, and to do that I need to have every user run guix pull (and by that I mean root will sudo -u $user guix pull), then update all of their profiles, and then guix gc --delete-generations. This ought to turn deduplication up to 11, and enjoy a reduced store size. I've already solved the cache size problem: mount -t overlay overlay -o \ lowerdir="/root/.cache/guix",upperdir="/home/$user/.cache/guix-overlay",workdir="/home/$user/.cache/guix-workdir" \ "/home/$user/.cache/guix" Then bindfs --mirror=$user /home/$user/.cache/guix /home/$user/.cache/guix This lets root (who just ran guix pull) share its cache with every user, and avoid blasting away 700MB of disk space in every $HOME to reproduce the cache. However, now, I'm facing the previously addressed problem of guix pull being slow and hungry: https://www.mail-archive.com/guix-devel@gnu.org/msg66442.html (Guix pull speed) https://yhetil.org/guix/87h6mwf4u3....@lapenas.dev/T/ (guix pull performance) On my server, in order to run guix pull, I have to stop all other services otherwise I run out of ram. Then, one root has pulled, I need to wait 4 minutes /per user/ for guix pull to finish its "Computing Guix derivation" step. I would like to know two things, one is for the sake of knowledge, and the other is to solve the problem at hand: - Why is this step not substitutable ? The inputs are known, a hash can be derived, a substitute server could be queried for an output of that hash ? What am I missing ? Does the guix derivation not end up in the store ? What makes it so special that it can't be served by a substitute server ? - Is there a way (even a very dirty one, like hand copying stuff accross /var/guix/profiles/per-user/*/current-guix) I can stop paying this 4 minutes per user price ? As I said, this is downtime on my server, as I need to stop all other services to let guix pull finish. Thanks in advance. Sorry for beating a dead horse, it's just that I can't scale anything up until I solve these performance issues. Sure I could rent a bigger server, but that's just kicking the can down the road. Cheers, Edouard.
