I installed "The Perfect Server" on my 512Mb RAM Ubuntu 10.10 VPS following this excellent guide. http://www.howtoforge.com/perfect-server-ubuntu-10.10-maverick-meerkat-ispconfig-3-p4 But it says: And sure enough, if I run apache2 -l I get: Code: Compiled in modules: core.c mod_log_config.c mod_logio.c prefork.c http_core.c mod_so.c I've had continuing memory and resource issues whatever I tweaked, and then I saw the following guide: http://www.devside.net/articles/apache-performance-tuning Excuse my newbie-ish questions, but after having had a good poke around, I'm still not sure if and how I can swap the running versions of Apache. I just want to try running worker instead of prefork for a day or two to see how it goes. How can I achieve this? Thank you!