Atomic Host upgrade

Fedora Atomic Host installations use the rpm-ostree deployment method, where packages are assembled on the Fedora release engineering side and delivered as atomic units, rather than the yum/DNF method of client side assembly. Consequently, they do not use the DNF system upgrade mechanism which is used to upgrade between Fedora releases for other Fedora installations. Instead, use the procedure described here.

One OSTree repository per release
It's crucial to note that at the moment, Fedora uses separate OSTree repositories for each major release. This makes switching between versions more painful. For more information, see this ticket.

Known issues:

• You must currently "setenforce 0" before upgrading. https://bugzilla.redhat.com/show_bug.cgi?id=1309075

Upgrading:

Let's assume you're upgrading from Fedora 40 to 41. First, you'll need to remove the remote for the previous major version:

sudo ostree remote delete fedora-atomic

Next, add a remote for the new major version:

sudo ostree remote add fedora-atomic --set=gpg-verify=false https://dl.fedoraproject.org/pub/fedora/linux/atomic/41

Then, rebase to it:

sudo rpm-ostree rebase fedora-atomic:fedora-atomic/41/x86_64/docker-host

Like any other rpm-ostree update, this is staged for the next reboot, so to finally apply the update:

sudo systemctl reboot

That should be all!