[systemd-devel] systemd.volatile=yes

[Lennart Poettering]

f1;4803;0cOn So, 03.09.17 20:23, Tobias Hunger (tobias.hunger at gmail.com) wrote:

> Hi,
> 
> I have been running a system based on a tmpfs as '/' and with a
> read-only /usr for a while now and am rather happy with that setup. I
> added "mount.usr" and similar flags to systemd ages ago, so that I
> could configure that setup via kernel parameters. That has worked
> great so far.
> 
> Recently I saw "systemd.volatile" in the documentation (e.g. here:
> https://www.freedesktop.org/software/systemd/man/kernel-command-line.html)
> and that "mount.usr*" is no longer documented. So I thought I'd move
> over to the new way of doing things. The change was pretty simple to
> do, I moved from "rootfs=tmpfs root=tmpfs rootflags=default
> mount.usr=/device/path mount.usrflags=ro mount.usrfs=somefs" over to
> "systemd.volatile=yes root=/device/path rootflags=ro rootfs=somefs".
> Much simpler, nice:-)

Hmm, mount.usr= should continue to be supported. It's documented in
the systemd-fstab-generator man page however, not in the
kernel-command-line one. We should fix that however, can you file a
bug?

> The one pitfall I ran into is that I had to add a "usr" folder into
> the usr partition for systemd-volatile-root.service to work. The
> system boots well and seems to work nicely with this change.

Uh, this shouldn't be necessary. Can you file a bug? I am really
surprised by this I must say... In my testing it didn't do that
either...

> But then I discovered one strange problem: I can not ssh into the root
> account anymore!
> 
> ssh -v shows that a connection is established, then ssh is checking
> for key files in /root/.ssh and does not find anything in there. Doing
> "ls -alF /root/.ssh" as root does list keys there.

This is very strange... Did you check that the perms of eahc component
of the path to /root/.ssh/[keys] actually are the same in both cases?

Lennart

-- 
Lennart Poettering, Red Hat