Re: Server inaccessible after upgrade from 7.5 to 7.6

Thanks for all your answers.

I had the opportunity to see the console screen and it turned out that
the file system was started in read-only mode. The dmesg was full of
"read-only" messages.

After doing a few fscks in single user mode, the system started up fine.

The real question is;
this is a VPS, I always (occasionally) issued clean resets/shutdowns,
and how did it get like this?

And by the way,
what does the -F switch in the "MARK FILESYSTEM CLEAN" question do? I
would always do 'y'.

Best,

Mark.


On Fri, Oct 11, 2024 at 7:22 AM Nick Holland
<nick@holland-consulting.net> wrote:
>
> On 10/10/24 14:14, Sebastien Marie wrote:
> > Mark <markbsdmail2023@gmail.com> writes:
> >
> >> Hi.
> >>
> >> I got 2 VPS, yesterday I upgraded one, from OpenBSD 7.5 to OpenBSD 7.6
> >> (amd64),
> >> today I wanted to upgrade the remaining one, after "sysupgrade -nk" and
> >> "reboot",
> >>
> >> I cannot login to the system anymore (I manage only via SSH), Putty says:
> >> "Remote side unexpectedly closed network connection",
> >> after entering the password of my root user. I tried ssh in the Windows
> >> terminal, same thing happens.
> >>
> >> ssh server is running, login: prompt arrives. And I see that my ssh client
> >> disconnects after issuing the correct password.
> >>
> >> If the password is wrong, it attempts to ask for it again.
> >>
> >> I got no physical or console access to the server.
> >>
> >> Any idea would be much appreciated.
> >
> >>From your description, I assume your shell is from ports (bash, zsh,
> > ...), and that after the upgrade of base, the binary of the port (from
> > 7.5) doesn't run on 7.6 system for some reason. So, sshd runs (it is
> > 7.6), you connect : sshd execve the shell, and it doesn't ends well.
>
> that was my first assumption, too.
>
> > You can try to connect to another user (if possible) using some base
> > shell, or try to get a console (the getty) and logs as root (assuming
> > the shell of root is still ksh).
>
> Might try this:
> ssh remotehost ksh
>
> it will probably look like it hung, but it might not be -- you are just
> sitting at ksh without $PS1 (or much of anything else) set. You might
> be able to gain control of the system sufficiently to run pkg_add -u.
>
> Here's an actual demo:
> $ uname -a
> OpenBSD fluffy3.in.nickh.org 7.5 GENERIC.MP#171 amd64
> $ ssh dbu1 ksh
> uname -a # note lack of prompt, motd, or anything...
> OpenBSD dbu1.in.nickh.org 7.6 GENERIC.MP#337 amd64
> # but I'm in!
>
> you can get around some of the no prompt/no motd stuff by
> doing "ssh <host> ksh -li", but it's still quite weird.
>
> you know all those times when you said, "I don't need to know
> 'ed(1)'"? well...maybe you now need it.
>
> Warning: when I promoted myself to root, the PW echoed on the screen.
> So...beware of shoulder surfers. :)
> (and I'm sure there are fixes for all these issues, but I didn't hunt
> very hard)
>
> Nick.
>