Ubuntu server not responding after upgrade

Question

I upgraded from Ubuntu 8.x to the latest version via the command-line. The installation appeared to work fine, no errors, but now I can't log on to the server through SSH and my website no longer resolves. I just get timeout errors.

I do have access to a very basic web form that allows me to execute commands on the server, but it is limited. I also have access to a process manager.

I attempted to start / stop sshd and also rebooted the server. When attempting to update through this web based console I get the following errors:

Err http://archive.ubuntu.com lucid Release.gpg
Temporary failure resolving 'archive.ubuntu.com'
Err archive.ubuntu.com lucid-updates Release.gpg
Temporary failure resolving 'archive.ubuntu.com'
Err archive.ubuntu.com lucid-security Release.gpg
Temporary failure resolving 'archive.ubuntu.com'
Reading package lists...

Any help would be appreciated.

Answer 1

Try this:

echo nameserver 8.8.8.8 > /etc/resolv.conf

Then restart SSH again. Your inability to connect to SSH might be caused by it trying to do a reverse lookup on your IP when you connect. If you don't have a valid DNS server set, this would take a very long time to timeout.

If not, check your logfiles:

tail /var/log/messages; tail /var/log/secure