I just set up an IPVS using 4 servers of which 3 are WHM/cPanel. 1 box, is running ipvs. This box routes all requests to 2 servers running apache and that are whm/cpanel. These 2 boxes then use the last whm/cpanel box for mysql & exim. All un-needed services have been un-installed. The setup uses both public and private ip addresses. We have the 2 web servers routing all email to the db server which doubles as the exim server. The 2 web servers have had their gateway on the nic to point to the ipvs box. With the ipvs box we have also routed public ip addresses to their respective whm panels on the webs. On the extreme, we have also installed memcache on the 2 web servers and are using these in a memcache add server array. All 3 whm/cpanel servers are running centos 5, with dual quad core xeons, each wtih 4 gig ram. All have dual nics as well. There was a lot of configuration done to get these to work properly, but the site is screaming fast now.. I will try to break it down in detail, the config and the steps we took, if anyone has an interest?