Virtual Server hitting memory resource limits?

Question

I have an Ubunto 10 VPS with 768RAM running virtuozzo & plesk.

I host two basic wordpress blogs on it and the most visitors I've had to the site are 2000 for one day and 1200 for three days (incl bots)

When the vps started to cause problems with pages loading I asked the hosts about it and they say the memory is hitting resource limits... (they said on 32k occassions)

I know absolutely nothing about servers - this was meant to be a learning exercise- but why would it be hitting resource limits so often when its got so little on it? I was told for what I wanted it for the RAM would be more than sufficient and now they're trying to get me to buy some more which I cant afford. What kinds of RAM should I upgrade to if I have to? Is there a way to sort it without forking out more cash?

Are there any tweaks/optimisations I should make to the server to improve how it works first?

thank you in advance (and please explain as if talking to an idiot - for surely in this case you are)

Answer 1

It sounds like you could use some swap, or more memory. As a side note, I answered a similar question here and that seems to have done the trick for that particular OP. I'm not sure that my exact answer (the code sample) will help you, but it may point you in the right direction.