Outgrowing my server

I’ve been running a Linode supplied UML virtual server for the best part of two years now. I have been extremely happy with it, but I’m now repeatedly running into performance problems with it, and things will only get worse. Basically the problem is Ruby on Rails, and more specifically the Typo weblog software. Ditching RoR is not an option because I host more than one application (with more to come) on it, and whilst I could ditch Typo for something lighter (but still RoR based) I don’t want to – even though that decision is mainly based on inertia. However I need to do something because occasionally my server will be brought to its knees and I get sick of sorting it out, especially as I host other sites on this server. Although I could switch to some managed RoR hosting, my preference to to host my own because I although I don’t like solving problems, I do like causing them! :)

As I see it, I’ve got the following options:

Pay for a bigger Linode Buy another VM and move either the Rails apps or the other sites to there Switch to a Xen hosting provider Some combination of the above

Before I make a final decision, has anyone got any suggestions/advice (other than ditch Rails)?