Tonight I attended a meeting of the BYU UUG about LVS. The focus of this presentation given by Lloyd Brown was an introduction to LVS and it's potential. The environment in which Lloyd uses LVS is quite simple and basic, but effective. His purpose was to balance the load of SSH across multiple computers with one entry point, but not concerned with high availability. LVS has one weakness (on its own). The setup calls for one director and only one director. That means that if the director goes down, it all goes down. But thanks to Linux-High Availability it is possible to set LVS up in such a way that if the main director went down, a backup can take over on the fly.
With that in mind, I was thinking of expanding on that idea. What if one used LVS-NAT for the configuration and setup the nodes (real servers) to get their configuration and filesystem via PXE? I know it is possible to boot Linux in such a way, but admittedly haven't done it before. The reason I'd want to have it PXE boot is because it would then be a simple matter to keep say a website up-to-date on all the nodes, and it is very simple to expand the cluster by simply getting a box and adding booting it. Using the heartbeat method of high availability, one would have a cluster that is highly scalable, easily scalable, and highly available.
When dealing with a handful of nodes this would most likely be overkill, but if one was dealing with 15-??? nodes, this would almost be necessary. My first step will be to PXE boot Linux by mounting the filesystem via NFS. Then I'll setup LVS for a simple website. Finally, I'll setup the heartbeat for high availability