On Sep 6, 2006, at 12:40 PM, Vincent van Scherpenseel wrote:
>> "top -o size" will show you which processes are requiring lots of  
>> memory; it's possible that one of them is leaking, or it may  
>> simply be that you are trying to run too much on a machine with  
>> limited RAM.  Increasing the amount of RAM in your machine is  
>> probably going to improve the performance of the system  
>> significantly...
>
> The strange thing is that it's a very low loaded machine, only  
> running an SMTP server for my daily mail (about 50 messages a day)  
> and a webserver for my personal website (http:// 
> vincent.vanscherpenseel.nl). Most of the visitors are spambots  
> targeting the blog comment system (I really need to implement a  
> CAPTCHA check, I know).
>
> Here is the top output of top -o size:
>
>   PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU  
> COMMAND
>  9747 www       -4    0    35M    4K semwait    0:32  0.00%  0.00%  
> httpd
[ ... ]

Ah, eight to ten 35MB apache children will consume most or all of  
your RAM and swap space.

Apache normally uses a lot less; a stock Apache-1 without anything  
expensive will take 5-8MB, and even Apache-2 + mod_perl or PHP takes  
around 15 - 20MB; perhaps you can reduce the max # of children  
running or remove a module or two that is bumping your memory usage  
up so much...

-- 
-Chuck