Hi

Newbie questions... I know how to use Virtual Hosts with Apache. Actualy I run thee domains with one Apache at my School. I do have some questions:

1- When dealing with many clients, How Apache is configured to run for multiple sites without using Virtual Hosts?... Do I need one Apache Server per cutomer? or here is where Control Panel Takes Action?

2- What is the optimal number of domains that can be run with one Apache Server?

a- Through Virtual Hosts
b- Through other mechanism

3- What's the optimal number of host to be hosted with one server (hardware dimension)? Let's say Dual XEON 2.4 GHZ, 1GB DDR RAm Linux Red Hat and plenty of hd + 400GB Monthly Transfer

TIA

Well,

1. You can't have multiple sites without using virtual hosts.
2. Apache forks many individual processes per request, so it's not limited by how many sites per apache server, it's limited to your hardware.
3. Optimal number of sites? Well, that's debatable. Depends on how intensive each site is. Let's say roughly 100. Probably more, depending on how much strain each one puts on the machine.

you can run seperate iterations of apache but not recommended. Each iteration can use a different conf file too.

1. You can't have multiple sites without using virtual hosts.
Individual IP per host, you can, but it's wasteful until ipv6

2. Apache forks many individual processes per request, so it's not limited by how many sites per apache server, it's limited to your hardware.
Correct, apache keeps a set number of spare servers open, uses those and forks a seperate spare server, cuts down on resources and response times.

3. Optimal number of sites? Well, that's debatable. Depends on how intensive each site is. Let's say roughly 100. Probably more, depending on how much strain each one puts on the machine.
I'd say roughly 80-120 aswell, considering his hardware.

What's the optimal number of host to be hosted with one server (hardware dimension)? Let's say Dual XEON 2.4 GHZ, 1GB DDR RAm

A server like that can easily handle 200-300 sites if they are not resources intensive (CGI/MySql/JSP, etc).