Thanks, all of you for trying to help me out here. The reason of the (experienced) sluggishness of OpenACS/PGSQL/AOL is a lot clearer to me now! I understand a lot of you tell me to buy more memory or suffer the consequences. As I said earlier: that is not an option, I am supposed to try OpenACS out and do so on the machine I have.
Of course I understand that quality has a price. We are trying out OpenACS however not because of it's stability etc. but because of the possibilities it offers as a community system. Eventually we will have a much better machine to work with OpenACS, so if memory is the main bottleneck, I suppose that bottle will be capped soon enough.
I consider my question suffiently answered: Aolserver is eating memory like a vampire sucks blood because of it's caching work, postgres is rather memory intensive too, and openacs does not make this any less so.
Thanks for helping us out here! Time to grab a cold one now, cheers!
