Long Cheng's questions

I have a webserver running on an IBM blade, hardware configuration is:

Intel Xeon E5506 x 2 (8 cores)
12G mem
SAS disk raid1

I use this box as a dedicated webserver serving a dozen of simple php scripts. They do mysql queries and return result codes. There is no pictures, no static files. The mysql server runs locally. Currently I'm using apache2. The purpose is to serve as many clients as I can using this server. I'm wondering what is the best value for the following configuration parameters:

MinSpareServers
MaxSpareServers
MaxClients

I'm also thinking of switching to nginx + php fastcgi. If I use this type of setup, how should I configure:

how many fastcgi processes
how many worker_processes
worker_connections

Please give your recommends based on your experience. Thanks!

On my debian 5.0 server, I setup some iptables rules like below:

ACCEPT     tcp  --  eee.fff.ggg.hhh      aaa.bbb.ccc.ddd     tcp dpt:80
DROP       tcp  --  0.0.0.0/0            aaa.bbb.ccc.ddd     tcp dpt:80

aaa.bbb.ccc.ddd is my server's ip address, and eee.fff.ggg.hhh is the other server which is the only one allowed to access the port. I noticed that there is inet6 addr setup on my server, and also netstat shows that apache2 is listening on tcp6 address:

tcp6       0      0 :::80                   :::*                    LISTEN

Do I need seperate iptables rule for ipv6 address? If so, how can I do so? I know nothing about ipv6. Thanks! do I must do so? If I don't use ip6tables, will someone bypass the iptable rule and connect to my :80 port through ipv6 address?