SSH doesn't run properly after boot

[tofagerl]

Openssh-server gives an error after boot forcing me to manually restart the service from a tty. This is a headless box, so that's not what you might call "practical"
Error:

ssh_exchange_identification: Connection closed by remote host

[cariboo]

Try running:

ssh -v user@server

that should show you the error, if not add another v

[markbl]

Look in /var/log on the server for any sshd error messages.

[tofagerl]

This is all I found: fatal: Missing privilege separation directory: /var/run/sshd

That directory exists now, though, and the message was three days old. I've rebooted several times since then, with SSHD not accepting anything.

ssh -vv gave nothing, but then that was run clientside, so I'm not sure what you were looking for...

[markbl]

This is all I found: fatal: Missing privilege separation directory: /var/run/sshd

That directory exists now, ..

You gotta be concerned how such an odd issue arose though? I suspect you have other problems in your installation. Perhaps flush and reinstall on your server?

sudo aptitude purge openssh-server
sudo aptitude install openssh-server

[tofagerl]

Well, this happened about a week after I formatted and installed 12.4. I had used arch just for fun, but it was driving me up the wall, so I went back to ubuntu for stability.

I might do a complete reinstall, it wouldn't be a huge problem for me, but as far as possible I'd like to know what went wrong first.

[Lars Noodén]

Does /var/log/syslog say anything about sshd's startup? What about stopping sshd and then starting it manually in debug mode?

sudo service ssh stop
sudo /usr/sbin/sshd -Dd

[tofagerl]

This is still happening. There's nothing in syslog when I grep for ssh.

[Lars Noodén]

Was there anything telling from "/usr/sbin/sshd -Dd" ?

[tofagerl]

Yes and no...

stop: Unknown instance:

It's a headless server, so I can't manually stop and restart the server, it has to be in one line.