On Thu, Jul 2, 2020 at 12:05 PM Daniel P. Berrangé berrange@redhat.com wrote:
On Thu, Jul 02, 2020 at 03:53:26PM +0000, Zbigniew Jędrzejewski-Szmek wrote:
Hi,
this is partially an outgrowth of the discussion about btrfs as default, but makes sense independently too...
It would be great if we could fairly reliably boot with a read-only root file system, all the way to the graphical environment. Obviously, such a machine will not be fully functional, but for users, debugging a disk problem when they have the normal environment with windows, tabbed terminals, graphical editors, and internet is vastly easier.
It also creates an image of robustness. Imagine that instead of being rudely dropped to a terminal prompt, the user is instead able to log in as usual and see a popup like
Your home directory is read-only. Do this and that. See https://...
Is the goal to have *everything* working? No. Some services will and should fail. If I have a database or anything else which only makes sense with permanent storage, failing early and loudly is appropriate. But services which need writable storage only tangentially or not at all should be robust and not fail. Journald behaves in a fashion where it stores logs to /run during early boot and them flushes them to /var/log when that becomes available. If /var/log never become available, we have a functional logs, with journalctl showing previous and current boot just fine. The only caveat is that logs for current boot will be lost upon reboot. Such graceful failure should be the norm.
I presume you're referring to regular Fedora here, but this description feels like it is approx asking for what Fedora Silverblue has delivered, only with the writable area for apps being just a ram disk with no persistence.
Silverblue fails when the disk can't mount as read-write either. So this benefits Silverblue by making it possible for those failure modes to work properly.
-- 真実はいつも一つ!/ Always, there's only one truth!