On Thu, Jul 2, 2020, at 11:53 AM, Zbigniew Jędrzejewski-Szmek wrote:
It would be great if we could fairly reliably boot with a read-only root file system,
Eh, just mount a tmpfs for /var, and an overlayfs for /etc (backed by a tmpfs).
That's what we do for Fedora CoreOS based live images, see https://github.com/coreos/fedora-coreos-config/blob/testing-devel/overlay.d/... It works.
(Which we recently switched to involve a loopback-mounted xfs on tmpfs because SELinux, but that is mostly only necessary because we want to support Ignition which does system provisioning in the initramfs, which is not true on non-Ignition based systems)