By default, Gentoo is using the rsync protocol to distribute it’s portage tree. For synchronizing a lot of smaller files, this protocol is rock-solid.
However, this method comes with a small drawback. To ensure the integrity of the downloaded files, they are signed with an OpenGPG key. First, the files are downloaded into a quarantine directory. Afterwards, portage is trying to validate the signatures and only if the signatures match the local portage tree will be overwritten with the newly synced files. The problem with this method is that the signature check is pretty slow, especially on lower-end systems. In my experience, it can take up to several minutes until the update is completed.
Fortunately, we can tell portage to use git instead of rsync for updating the portage tree.
Since the Gentoo developers are only accepting signed git commits, we don’t need additional signature checks here since the commits themselves can be considered as valid. Since running
emerge --sync is nothing more than a simple
git pull, the synchronization only takes a couple of seconds.
The configuration takes place in the file
/etc/portage/repos.conf/gentoo.conf which should then look like this:
[DEFAULT] main-repo = gentoo [gentoo] location = /var/db/repos/gentoo sync-type = git sync-uri = https://anongit.gentoo.org/git/repo/sync/gentoo.git auto-sync = yes sync-git-verify-commit-signature = yes sync-openpgp-key-path = /usr/share/openpgp-keys/gentoo-release.asc
After changing the configuration file, it’s necessary to delete the local portage tree (which resides in
/var/db/repos/gentoo by default) once since the initial
git clone will fail otherwise.
As you can see, the configuration is now looking a lot slimmer. All lines beginning with
sync- are not needed anymore and can either be deleted or commented out.
One note regarding the
sync-uri: In addition to the servers hosted by the Gentoo infrastructure team it’s also possible to use the GitHub mirror hosted at https://github.com/gentoo/gentoo.
In case you are using your own (additional) repositories, it is still possible to include them by using rsync since the synchronization options can be configured per repository.
Update: As holgersson pointed out in his comment, the git synchronisation doesn’t do any verification at all. Therefore it’s recommended to enable
sync-git-verify-commit-signature as shown above. Thank you!