Sorry for not replying for a while. I was quite busy the last couple of days. I do believe, that swap usage has stopped increasing ever since I changed swappines to 0. I have also not observed any adverse effects of this change. I will now try this, to clear the swap without having to reboot, and cross my fingers it doesn't start growing again. I'll also make the swappines change permanent, by setting vm.swappiness=0 in /etc/sysctl.conf. I'm not sure I entirely understand this. So, is 270MB per apache process normal? Thank you very much for taking the time to help me solve this problem, bajodel. It appears, for now, that the swappiness setting did the trick. I would never have figured this out on my own.