Been using Gentoo since 2004 on all my machines. They won me over after I started playing around with their Unreal Tournament demo ISO.
The game changer for me was using my NAS as a build host for all my machines. It has enough memory and cores to compile on 32 threads. But a full install from a stage3 on my ageing Thinkpad X13 or SBCs would fry the poor things and just isn't feasible to maintain.
I have systemd-nspawn containers for the different microarchitectures and mount their /var/cache/binpkgs and /etc/portage dirs over NFS on the target machines. The Thinkpad can now do an empty tree emerge in like an hour and leaving out the bdeps cuts down on about 150 packages.
Despite being focused on OpenRC, I have had the most pleasant experience with systemd on Gentoo over all the other distros I've tried.
I'm so interested to learn more about this. Do you still run all your emerge commands on the thinkpad? What's the benefit of mounting /etc/portage over nfs?
I have this dream of moving all my ubuntu servers to gentoo but I don't have a clear enough picture of how to centralize management of a fleet of gentoo machines
Yes - still use emerge on the Thinkpad like I would on the host, like emerge -avuDN @world and such. This is the wiki article [1] I used to set up most the portage side of things, it covers NFS as well.
I use NFS to mount the container's /etc/portage to /mnt/portage and symlink the files to the Thinkpad's /etc/portage so I can cherry pick what I want to keep in sync with the build container. Don't have to mess with repos.conf either because portage will look to /var/cache/binpkgs by default.
make.conf is a directory on both machines and has files like 01-common-flags.conf and 02-binhost-flags.conf. The Thinkpad has 01-common-flags.conf and 03-target-flags.conf with EMERGE_DEFAULT_OPTS="--with-bdeps=n --usepkgonly" set, so running emerge -avuDN on the Thinkpad will only update with binaries from the mounted /var/cache/binpkgs. I keep the software in sync by using /etc/portage/sets instead of the world file. Then all the package.* dirs are symlinks as well.
The Thinkpad binhost is a znver3, so the build container has CFLAGS="--march=x86-64-v3 --mtune=alderlake" set. There's some SIMD extensions that two don't have in common and it has to build code that runs on both machines, otherwise you could use the target architecture in --march. Using the --mtune option in my case apparently sets the L2 cache size of the produced code to that of the Intel chip.
Systemd-nspawn containers are super easy to spin up, as you basically install Gentoo from stage3 and it works like a chroot but with a full init. I run updates irregularly, there's still some manual effort for maintenance, but it's mostly just kicking off emerge and letting it build in a tmux session.
[1] https://wiki.gentoo.org/wiki/Binary_package_guide
Thanks! A lot for me to learn here