Hi,

I am still runnig Redhat 9 box with sendmail and squid.  
 
 
how is squid configured? it can be configured to eat up quite a bit of RAM. if you tweak that to fit into your 512MB of RAM you may be able to get your machine running faster. have a look at what 'top' is saying, maybe iostat as well. someone else mentioned 'atop', it looks pretty slick if you can, give that a shot. by running 'top' you will also be able to see how much RAM Linux is seeing. make sure that it actually is 512MB.
 
 It is quite slow. It has only 128 MB RAM. So I upgraded it to 512 MB RAM. Now, It is running with 512 MB RAM. But, It is still slow. No progress has been achived. Some users say it is slower than before. Actually, I also have noticed it is NOW SLOWER than before. WHY IS THAT? 
 
if squid is configured to eat up a large amount of RAM, then it may be possible that it needs contiguous memory blocks, so it may be possible that it is eating all of your physical memory, and all of the rest of your apps are using virtual memory (read: swap space). I have seen something similar on an Oracle box. again, reading the output of 'top' will help you.