On Wed, Sep 06, 2006 at 09:40:55PM +0200, Vincent van Scherpenseel wrote:
> > "top -o size" will show you which processes are requiring lots of 

THANKS for teaching me about "top"!

> 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). 
[...]
>    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
>   9700 www       -4    0    35M    4K semwait    0:31  0.00%  0.00% httpd
> 11517 www       -4    0    34M    4K semwait    0:10  0.00%  0.00% httpd
> 12290 www       -4    0    33M    4K semwait    0:37  0.00%  0.00% httpd
>    363 mysql      2    4    33M 2884K select    25:29  0.00%  0.00% mysqld

Have you done something recently to your software?  I have an Apache2
running with all of the stock mods plus a few extras, and it's using
MUCH less memory than yours.  Also the database footprint is ten times
smaller.
  PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU COMMAND
  856 www       -4    0  4636K 2456K semwait    0:00  0.00%  0.00% httpd
 1081 www        2    0  4580K 1964K poll       0:00  0.00%  0.00% httpd
  732 www       -4    0  4580K 1964K semwait    0:00  0.00%  0.00% httpd
  922 www       -4    0  4580K 1964K semwait    0:00  0.00%  0.00% httpd
  443 www       -4    0  4580K 1964K semwait    0:00  0.00%  0.00% httpd
  950 postgres   2    0  3852K 1412K select     0:00  0.00%  0.00% postgres

> Could it be that my harddisk is somehow faulty and the processes hang on 

Before looking at hardware, I'd try to get some advice as to why your
processes are eating up such a huge amount of memory.

-- 
henry nelson
  WWW_HOME=http://yuba(dot)ne(dot)jp/(tilde)home/