Paul Scott wrote:
If the former (ignorant question on my part) how do I log in via ssh?
Install and configure sshd. Use an ssh client on another machine to login
to your "frozen" machine. If the machine isn't really totally hosed, you
can do this. Then su to root and try killing X. As a last resort, use
shutdown to turn the machine off gracefully.
If you don't want to hassle with ssh, you can settle for telnet as long
as you make sure that there's no way to connect to it from the Internet.
If you have only one machine, or no local network, then obviously this
won't work for you. Another possibility would be to buy a cheap used
serial terminal and compile support for serial-port consoles into your
kernel. I used to have one of these. It came in handy at times.