managing same domain name with multiple sub domains with different physical servers

view story

http://serverfault.com – I am having one primary temp domain www.product.com For each client i need to have separate sub domain mapped to same server with same port(80) through virtual host. www.client1.product.com www.client2.product.com www.clientn.product.com what's my problem is my server reaches maximum load, so i am unable to add additional clients. my current setup www.product.com is mapped with server 1 using only 1 ip address server 1 using www.client1.product.com www.client2.product.com . . . www.client20.product.com Here is my actual problem now server1 reaches maximum utilization of physical (HowTos)