[Memory] No more availeble, server stops working

[J0s3ph]

Hello,

I have a VPS, with 512MB of RAM. I followed the ISPConfig 3 tutorial. Now nearly all my RAM and Swap space is used. More, all the free memory is gone and the server simply stops working.

Going to my site displays a blank page, SSH won't connect, and with the still logged on SSH:

sample command

-bash: fork: Cannot allocate memory

Even reboot shows that.

Any ideas?
Thanks!