performance ubuntu

Hi all,
I'm running a zen Based VPS at blacknight with some, relatively speaking, low traffic sites.

I upgraded one of those sites to Drupal 6 this morning, and now the server seems to have gone haywire.

I'd appreciate any advice as to how to recover the situation.

One of the sites is www.athenryac.com, and judging from the browser, a connection is being made to the server,
and it is is either extremely slow, or just times out.
Even ssh access is very slow.

The server is running Ubuntu 8.4.01
Php 5
with APC installed.
Mysql 5.

Phpinfo, and my.cnf pasted below.