Here is what DreamHost has to say:
We're upgrading your shared web server's operating system to Ubuntu 12.04
this Saturday, November 8th at 8PM PST. Your sites may be unavailable for
approximately 30-40 minutes during this upgrade. We're very sorry for any
inconvenience this may cause.
Joseph
Joseph Puentes
Clean@h2opodcast.com
http://h2opodcast.com/vsse.html