how to monitor system resources etc

[Chad Leigh -- Shire.Net LLC]

Hi

I am having a problem with apache/php/mysql or something.   One 
customers stuff tends to blow the machine up. I would like to be able 
to monitor stuff and never remember the tools etc to monitor  things.  
Process slots,  memory, buffers, etc.  (I always remember how to look 
at mbufs buffers though) or whatever else I can look at and see if we 
are hitting a limit.  Any pointers to stuff that explains the best way 
to track things down would be great.

This is on 4.9/10 for now.

Sorry for being so vague.  I am not getting anything in 
/var/log/messages and the mysql and apache logs don't give a lot.

Symptoms are lots of httpsd child processes in sbwait and a few in 
lockf state.  All of a sudden load goes up from <1 or 1-2 range to over 
200 and the swap space starts to rapidly fill (I suspect load is caused 
by the excessive swapping).  The swapfile is getting up to about 55% 
full before it starts to fix itself).  (2GB RAM, 4GB swap --- 2 x 2gb 
-- dual AMD Athlon MP machine). It will fix itself after a while and 
the load will go down as will the swap usage, but mysql or the php 
stuff or one of them is still hung up and won't respond.  The apache 
only handles this site. Other customers have their own apache 
installations.

Apache is 1.3.33+ssl (ben-ssl)
Mysql is now 4.1.9
php is 5.0.3


Thanks
Chad